I think people are getting confused here. From what I've read this can only be to replace the Champions League, not the domestic leagues, for the clubs involved. It's the same format as the CL without the need to waste game time playing the 'shit clubs'. And why would any of these 11 clubs want to base their existence around playing in two almost-identical competitions where a bad year could see you playing just 12 games? Even if it were possible to qualify for the UEFA Champions League without playing in a UEFA domestic league. It's unrealistic, unachievable, unworkable nonsense. Not that that alone is enough to stop anything these days.
This is just a power grab by the big clubs v UEFA as always happens every few years. The only potential breakaway I think would be good is if all the big, financially-sound, well-supported clubs like us, United, Bayern, Dortmund, Arsenal, Spurs, Atleti, Roma, Ajax and Celtic et al threatened a break from the cheating shite like PSG, City, Chelsea, Real so UEFA either reel them in or be stuck with a competition full of fraudsters and dross. Football might actually improve then.