No one is going to be interested in watching a Nice vs Hammarby tie; I can guarantee you that.
Everyone will if the best players are there.
If 2-3 big clubs go bankrupt, then the players from those big clubs will still have to play somewhere. And because of the players, fans will start following those "new" teams.
Actually, put Chelsea and Real in a lower division and distribute their players around Europe, and you suddenly get at least 7-8 more attractive clubs.
Never as in the last years the quality players, all of them, have been shared between 5-6 clubs only, with some 3-4 teams having 80% of all the superstars.
Back in the days the limit on foreigners was preventing a club from creating an international world class starting XI and a world class bench. Now nobody can stop Real from paying 25m eur for a sub player and that sub player will warm the bench in Madrid instead of playing for Ajax or Dortmund and make those teams much better.
With the new rule Real won't be able to buy anything that moves and they won't be able to afford the luxury to overpay for a bench player. That guy, instead of being bought by Real will need to play somewhere else and will play somewhere else.