The -datacarrier
option is redundant, as disabling the relay and mining of transactions creating OP_RETURN outputs can be accomplished by setting -datacarriersize=0
. Its removal was supported by several people in the discussion of #27261 (e.g. #27261 (comment), #27261 (comment)) and implemented in #28130, but that PR was rejected due to making other, more controversial changes.
Being a breaking change, this will of course need a release note. I’d recommend anyone concerned that they might accidentally start relaying and mining OP_RETURN transactions to proactively set -datacarriersize=0
now.