In order to dissolve the unions during the time it was legal - they would have to keep them legal so they could divorce. Once they divorce they could not remarry and if the rate is as high as I have read there probably only about 5000 that are still legally married.
That may be an interesting challenge down the road though, i.e. “I was married before, now divorced, now I can’t remarry? Discrimination!”
It does seem that the court gave the gay agenda crowd some wiggle room for future challenges.