Been the case since #28476 (see post-merge discussion). Still the case with master + LLVM 17.0.2.
i.e inside the msan fuzz CI container:
./ci_container_base/ci/scratch//build/bitcoin-x86_64-pc-linux-gnu/src/test/fuzz/fuzz
==29842==WARNING: MemorySanitizer: use-of-uninitialized-value
[#0](/bitcoin-bitcoin/0/) 0x556ca7b9b27f in SetArgs(int, char**) src/test/fuzz/fuzz.cpp:48:5
[#1](/bitcoin-bitcoin/1/) 0x556ca7b9b27f in LLVMFuzzerInitialize src/test/fuzz/fuzz.cpp:185:5
[#2](/bitcoin-bitcoin/2/) 0x556ca73f18a3 in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) /msan/llvm-project/compiler-rt/lib/fuzzer/FuzzerDriver.cpp:647:5
[#3](/bitcoin-bitcoin/3/) 0x556ca741fb92 in main /msan/llvm-project/compiler-rt/lib/fuzzer/FuzzerMain.cpp:20:10
[#4](/bitcoin-bitcoin/4/) 0x7f7f1d7f7d8f (/lib/x86_64-linux-gnu/libc.so.6+0x29d8f) (BuildId: 229b7dc509053fe4df5e29e8629911f0c3bc66dd)
[#5](/bitcoin-bitcoin/5/) 0x7f7f1d7f7e3f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e3f) (BuildId: 229b7dc509053fe4df5e29e8629911f0c3bc66dd)
[#6](/bitcoin-bitcoin/6/) 0x556ca73e48b4 in _start (/ci_container_base/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/test/fuzz/fuzz+0x8268b4)
Member fields were destroyed
[#0](/bitcoin-bitcoin/0/) 0x556ca74af2dd in __sanitizer_dtor_callback_fields /msan/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:982:5
[#1](/bitcoin-bitcoin/1/) 0x556ca946bed8 in std::__1::unique_ptr<std::__1::__tree_node<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, void*>, std::__1::__tree_node_destructor<std::__1::allocator<std::__1::__tree_node<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, void*>>>>::~unique_ptr[abi:v170002]() /msan/cxx_build/include/c++/v1/__memory/unique_ptr.h:137:44
[#2](/bitcoin-bitcoin/2/) 0x556ca946bed8 in std::__1::unique_ptr<std::__1::__tree_node<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, void*>, std::__1::__tree_node_destructor<std::__1::allocator<std::__1::__tree_node<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, void*>>>>::~unique_ptr[abi:v170002]() /msan/cxx_build/include/c++/v1/__memory/unique_ptr.h:266:84
[#3](/bitcoin-bitcoin/3/) 0x556ca946bed8 in std::__1::pair<std::__1::__tree_iterator<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, std::__1::__tree_node<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, void*>*, long>, bool> std::__1::__tree<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, std::__1::less<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>, std::__1::allocator<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>>::__emplace_unique_impl<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&) /msan/cxx_build/include/c++/v1/__tree:2167:1
[#4](/bitcoin-bitcoin/4/) 0x556ca73e46e4 in std::__1::pair<std::__1::__tree_iterator<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, std::__1::__tree_node<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, void*>*, long>, bool> std::__1::__tree<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, std::__1::less<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>, std::__1::allocator<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>>::__emplace_unique[abi:v170002]<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&) /msan/cxx_build/include/c++/v1/__tree:1200:16
[#5](/bitcoin-bitcoin/5/) 0x556ca73e46e4 in std::__1::pair<std::__1::__tree_const_iterator<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, std::__1::__tree_node<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, void*>*, long>, bool> std::__1::set<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>, std::__1::less<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>, std::__1::allocator<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>>::emplace[abi:v170002]<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&) /msan/cxx_build/include/c++/v1/set:787:29
[#6](/bitcoin-bitcoin/6/) 0x556ca73e46e4 in CRPCConvertTable::CRPCConvertTable() src/rpc/client.cpp:342:23
[#7](/bitcoin-bitcoin/7/) 0x556ca73e46e4 in __cxx_global_var_init.224 src/rpc/client.cpp:346:25
[#8](/bitcoin-bitcoin/8/) 0x556ca73e46e4 in _GLOBAL__sub_I_client.cpp src/rpc/client.cpp
[#9](/bitcoin-bitcoin/9/) 0x7f7f1d7f7eba in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29eba) (BuildId: 229b7dc509053fe4df5e29e8629911f0c3bc66dd)
SUMMARY: MemorySanitizer: use-of-uninitialized-value src/test/fuzz/fuzz.cpp:48:5 in SetArgs(int, char**)
Exiting
