User blog comment:DaNASCAT/Technical Update: March 7, 2016/@comment-24832379-20160309074926/@comment-1251315-20160309082010

I think that is a bug, as anyone who is autoconfirmed is not supposed to see a CAPTCHA at all. If this is really expected behaviour and even long standing members of Wikia are forced to go through a CAPTCHA, I will not be happy, as anyone with a lot of edits on Wikia as a whole is unlikely to be a robot.