I work at Vimeo. We use automated detection to flag suspicious accounts. This was a clear false-positive, and the account has been unsuspended.

We don't convert urls to hyperlinks in video descriptions when the user has signed up recently, because hyperlinked urls have been used by spammers to trick visitors into visiting fraudulent sites.

This is clearly legitimate behaviour in context, but a brand-new user posting identical descriptions and urls on multiple videos is behaviour commonly seen in spam accounts, and we tend to err on the side of caution.

Edit: clarified circumstances under which urls are converted