Sorry, I was unclear. I mention my time constraints because I don't want anyone organizing this game jam to do _anything_ that they're uncomfortable with. I'd feel really bad if I pressured the organizers of this jam into doing something for me to not even participate. I'm repeating legal nuance that I was told to ask for rather than something I felt a desire to request personally.
As far as licensing, I just need the rules of participation to explicitly indicate that I maintain ownership of the content I submit. Among other things, it would allow me to freely apply the above license.
If it makes you feel better, I'm super embarrassed every time I have to ask a game jam to add this specific wording, but it's universal to every game jam or hackathon I've entered. I'm not trying to be adversarial to you to accuse you of attempting anything shady.