I'm not sold at the idea - for most projects it makes sense that the author of the PR should ultimately have ownership in the code that they're submitting. It doesn't matter if that's AI generated, generated with the help of other humans or typed up by a monkey.
> A computer can never be held accountable, therefore a computer must never make a management decision. - IBM Training Manual, 1979
Splitting out AI into it's own entity invites a word of issues, AI cannot take ownership of the bugs it writes or the responsibility for the code to be good. That lies up to the human "co-author", if you want to use that phrase.