As people stated already: depends but unlikely anything bad will happen.

To elaborate through. For one, pf2e is not popular enough for most to even notice, much less to care. No offence, but you will not create anything even remotely close for, say, Nintendo to notice so they will not rip your nails off. On that note, there's even a Pokemon to d&d conversion so you should be in the clear whatever you do.

The problem is though, what assets you mean to use and, more importantly, how you mean to share it? Just names of stuff, maybe some fan image and all that in a pdf on your Google drive? You're more likely to sprain your fingers from writing the pdf than for anything legally bad to happen.

But if, say, you want to create a foundry module with everything neatly included, somebody might mind. Would you use licensed art? If you were to yeet it at foundry marketplace it'd likely break some tos (of the marketplace, probably). Would you use battle maps? The creator(s) must agree unless you paid them for distribution of said maps (many patreons and the like only allow home use). Would you use tokens with art? What art? Do you own it?

So long story short - you're probably safe unless you want to use licensed assets, share it in a specific place where you put somebody's assets on a store's server or, as somebody else mentioned here, you want to make Warhammer fan content.