Further note that there are actually 0 modules built for rawhide, so it should actually just make a empty repo there I guess?

This is kind of expected: Pungi uses the list of modules in a variant to determine it's a modular variant. With no modules at all, the Modular variant looks exactly like Everything (except for the name). Therefore it gets the same content.

Adding an empty module might fix it. It would need to be listed in PDC and have a corresponding empty tag in Koji.

Alternatively you could skip Modular variant in the compose until it gets some content.

Commit 5c90259 fixes this issue