I can’t help wondering whether it’s going to make any difference to the sort of couples where one of them (more often the woman) would like a legal union, but the other doesn’t, because ‘it’s just a piece of paper’.
Only for him to take off after some, or even many years, with someone else, and marry soon afterwards,
I know of a few such cases and have heard of several more. It wasn’t that he didn’t want to make the commitment - he just didn’t want to make it with his former partner.