You need to ask staff. I don't think so. Other than users providing false information (accidental or otherwise) at registration, I don't see any legitimate reason one would need to change their birth year.
Also, even if you accidentally gave a wrong year, it probably wouldn't cause you any problems. This information isn't visible to any user other than Fandom staff. The only case you might face a problem is if your age is between 13-16 and you then reveal that you live in a country where the minimum age is 16 (Most of europe and California).