This is more or less my take on it.

I am not against AI code, it can be perfectly fine.

The principle issue in my mind is the rate of change.

Once you rewrite a code base like this (in a week no less) the only way to work on it in the future is using AI tools because no single person has any knowledge about any specific piece of code base any more.

AI generated code that is run through a classic PR process would potentially be fine, but then you sorta lose the entire point of using AI.