Redistribution would be a separate aspect, there are quite a few assets out there that are freely available, can be used in any game (often even a commercial one) but can't be redistributed on their own.
As long as access to them is completely free, they should be fine for this jam, if you provide references to where those assets can be gotten from.
Nonetheless, the best option would be to use completely free assets so one could just fetch the project and build it oneself without any extra steps...