fundrawtransaction allows users to add a change output and then not have it removed from keypool. While it would be nice to have users follow the normal CreateTransaction/CommitTransaction process we use internally, there isnt much benefit in exposing this option, especially with HD wallets, while there is ample room for users to misunderstand or misuse this option.
This partially reverts #9377. Would be nice to get this for 15 since its kinda crazy we have this option to begin with IMO, will need release notes as an RPC option is now ignored.