Earlier quoted context omitted.
A parody is constitutionally protected free speech. Yes, they can sue regardless, but I think your leverage is higher in that scenario. I am not a lawyer. I hope the creator has spoken with one in case.
Apple however is free to suppress anything they want in the app store, so I guess we'll see.
(sorry, couldn't resist)
It's also not free as in GnuBeer either, since as a general rule they generously decline to explain the reverses in policy (pet theory: it is based on the retrograde motion of Sirius the dogstar, since Apple is clearly controlled by the reptillian lizard-people from there)