Do you understand the the meaning of a closed league? Its still early days so we dont have all the info, but what is released and CONFIRMED is that this is a closed PERMANENT membership league, meaning no matter what, these 12 clubs keep their spot, no matter how they do on the pitch. Its not meant to replace the league (tho it might need to, if they arent allowed in their leagues), but the CL as you said. But the CL isnt a closed competition, anyone and everyone can qualify on merit, the winners are the richest, but everyone can compete to qualify into it (and 4-5 of current SL clus arent even good enough to qualify to CL...). Football has been money focused venture for 2 decades as is in its current state. But this is just a step too far.
SL is a marketing campaign bussiness venture, that you are invited and cant leave, based on how much money you can make together. 12 permanent members, and 3 unknown ones, plus few per year that will be lucky enough to be invited? And you dont get, how as a football fan, how this is being questioned? Really? They can change it to something else later, who knows, but for now that is whats confirmed, is not something to misunderstand as its presented. This simply about money, pure and simple.