It’s a complete strawman. Nobody is suggesting that any religion should be forced to marry a couple. And that’s not even a change; stroll up to the nearest mormon church and demand that they give you and youre spouse-to-be a proper temple marriage, see how well that works out.
So, yeah, Trisk’s concern there is about as sensible as being afraid the unicorns will eat you.
Good to hear that cleared up. Also, I should note that with a limited amount of googling, it appears prop 8 was sold to its supporters in no small part through this idea of churches being “forced to marry the gays”. So even if it’s completely obvious, it could help to be more overt about this fallacy.