Pointer comparisons ignore provenance

(1) is not semantically equivalent to (2). Under (2), if you tell me that pointers x and y are equal, then I am entitled to assume that they have the same provenance and so I can use either pointer to access the same object. Furthermore, (2) also extends to atomic compare-and-swap, meaning that you are required to ensure that the whole pointer-zapping problem described in the article does not arise in the first place (or at least, that the resulting binary behaves as if the problem does not arise).

(1) provides neither of those guarantees, so it is not equivalent to (2) no matter how lucky or unlucky I might get.