AI generated add on builds.
It can already spit out simple XenForo add on builds.
I made one by telling it to make everyone's signature X on install and then revert back to their original signature on disable/uninstall, and then I think I refined it to only change signatures for users of a specific user group. Obviously, I didn't have anything specific in mind, but it just went to show that it understands XF architecture already and could be used to make simple add ons, to even more complex ones provided the correct description.
I would have to play with it more next time I need a simple add on to see if it can deliver, then see if a developer could audit it to ensure it works, if it's too complex for me to understand myself.
By the signature example, it knows not to run direct queries, but I can't recall if they were clean (to prevent injection, etc.).
Edit: Read the thread title wrong, but a lot of the suggestions here, AI could implement in the current XF version by creating an add on for it — like use Chat GPT API (if it can respond with images) to generate an avatar based on the username chosen, save it, and let them edit it later if they want, as opposed to the default Letter for the one with no avatar set.