You’re highly encouraged to make the game yourself as much as possible without using AI! To me, the spirit of the jam is to find the time to make the thing you want to make without being too stressed about it. You have 2 weeks, there’s no ratings, no prizes, and the theme is optional! I hope people take this as an opportunity to learn more about developing games rather than trying to compete against others, and in my mind AI is usually used to take shortcuts that hopefully people aren’t tempted to take here.
That being said, if you do end up using AI assets you should always let your players know you did somewhere, probably wherever you credit any assets you’re using that you didn’t make, and let players come to their own conclusions about it themselves.