I unlocked wilbur with console commands (spawned soggy monkey, then spawned crown and used crown on monkey) and now wilbur has wilson's voice lines. His voice is still the same instrument, but it sets off my OCD.
Steps to Reproduce
Not have wilbur unlocked yet, then spawn soggy monkey (i did it on land) then spawn wilbur's crown. Use the crown on the soggy monkey, then exit the world. Once you use wilbur in a game, you'll notice his voicelines are identical to wilson's.
This issue has not been confirmed by a developer yet.