If California leaves marriage intact in November we have the potential for a full-faith-and-credit test case as there is no residency restriction there as there is in Massachusetts.
But even if they do pass an amendment, we still have a test case. While California can invalidate marriages performed there, it can't invalidate marriages performed in Massachusetts; it can only refuse to recognize them. California residents are now (or will soon be) allowed to marry here. And the 1913 law is concerned only with legality at the time of the marriage -- once they're married, they'll stay married.