Marriage rates have already been dropping and divorce is an available option. Removing that out isn’t going to increase people’s confidence about going into marriage.
And as the nightmare stories come out about the guys (and probably some girls, too) who change overnight once the marriage license is official (or annulment period ends or whatever becomes the “now you’re locked in as long as I don’t get caught cheating”), it’ll only go down further.
There will also be a reaction to the women who decide to just stop being loyal once they are done with a marriage but can’t get out.