I hate to be negative here, but I can't see this having any effect on the Glazers. They already know the fans don't like them and want them to sell the club. However, they won't even consider selling unless somebody matches their asking price of around £4billion. Even then they may not sell, they are sitting pretty 3,000 miles away drawing big dividend cheques unaffected by fans protesting in England. Plus if you think the idea of a Super League is dead, it wouldn't surprise me if they bring it up again in some other format in a couple of years. Also if there is a sale, who buys, the ruling family of Saudi Arabia, or a Chineses billionaire? That may well be a case of sticking with the devil you know, or of being careful what you ask for.
The other think that has been mentioned is this 50 +1, does the British Government have the authority to legislate that? I wouldn't think so, but I could be wrong, and I would imagine that practically ever club in the Premier will fight against it.