In a bad-vibes moment, they’re denying a huge outlet like IGN a review code. No matter what I think of IGN in particular (nothing good tbh), that’s not something I can find a real explanation for other than “We made DC’s Gollum and want to avoid bad press as long as we can”.
Nintendo is one of the most litigious game companies there is, and Palworld Dev is also based in Japan so there’s no international complications.
If Nintendo had an infringement case at all they’d already have buried Palworld.