Even if this policy were intended to be used this way, or winds up being used this way, (which I don't support), it still seems better than the alternative. If you reference your husband and somebody says "Aaah, political, can't say that" - do you want to be sharing personal details with this person? Would you prefer they engaged you in a debate about gay marriage or told you their anti-gay feelings? Prefer they sit in silence stewing with hatred of you?
If you have anti-gay coworkers who buzz you for anodyne references like this you could just not talk to them or buzz them for their references to wives, girlfriends, whatever. You could escalate to management or HR if you felt they were treating you unfairly.
If the corporate policy permits politics at worse, that would seem to make situation worse, not better.
