If you think Palworld constitutes parody, you've got an incredibly low bar for parody, considering all the marketing material is played 100% straight I think the whole poking fun narrative (and that alone isn't parody) is just your head and if they start selling palworld plushies, that's completely out the window.
like I said
given that it is a commercial product the standard for fair use is quite a bit higher, and the question will come down to whether or not Palworld creates consumer confusion, the game itself is 100% in the clear, and gameplay has to be nearly identical and not something generic to violate copyright (Tetris co brought down some tetris clone and atari stopped k c munchkin but fighter's history was ok despite being similar to street fighter 2 and karate champ vs world karate championship was all good despite looking like they could be the same game, but not copyright protected because a martial arts fight is a martial arts fight)
The character designs get murkier, especially if Pocket Pair tries to merchandise the pals they'll be under much more scrutiny and like I said earlier if they cause market confusion will be a big test. Which involves a mess of comparisons of similarity and percentages
