You should be good! (I might do the same actually, if I have time). I think rule 33 has more to do with jam-spam... there have been some submissions to previous MGGJs that were clearly submitting to as many jams as possible, and their games weren't really designed for them.
Down in the FAQs on the MGGJ4 frontpage it's clarified:
Can I submit my game into other jams?
- If it also fits that jam, yes. Feel free to do multiple jams in conjunction if it happens to coincide with MGGJ4.
- Beware though if you submit to so many jams, it might look suspicious. If I see your game being submitted to jams that your game doesn't actually fit into, even if your game fits my jam, I might question whether or not your game fitting into my jam is just a coincidence.