I think its a good idea to change the name of it. One of the main reason SSM currently isn't coming is they do not want to upset people. So a good solution i think would be to not call it marriage call it something else and build lore around it, Could even call it "Life Partners" ok not the best name but you can see what am going for. Take the word marriage away from it build it around the Lore of the world and done.