https://www.football.london/premier-league/champions-league-arsenal-chelsea-tottenham-18164019
Good God I hope this isn't true or doesn't come to pass. It's just more of Uefa being and old boys club and trying to assure only the same old "SUPER CLUBS* are in CL year after year. Step towards more of a Super league format. I might really be done with Champions League if this really happens.
It's always been more likely that competitions in other countries would become more closed than the US would end up with Pro/Rel. From a competition standard, UCL seems an especially poor choice for closure. But economically, it makes sense that it would happen there first. I think it's a natural outgrowth of the way Europe's biggest clubs have internationalized their fanbases.
The English Game carries very English historic ideals of fair play and open competition and the myth of the FA that the English exported to the world when they had an empire and the game and its culture spread through direct contact. The English don't have a monopoly on those ideals but the very English specific versions of them travelled with the game. So you see translated versions of it all over Europe, and even in the national leagues of countries around the world to different degrees.
But the way fanbases expanded in the last 20 years is different. For one, supporting a non-local team, one you not only don't live near but never did, is different. You're always an outsider, and the cultural extras still travel with, but the bond is weaker. I know more about Minnesota and Swansea than your average NYer, but I'm not of either place, and not even close. My support for those teams is much more mercenary than for my local teams (even though neither ever really won anything). I never think "the Vikings lost, but they did Minnesota proud and how nice they do all those visits to the local children's hospital" because I don't really care. It's just "f#ck, they lost again."
Doesn't mean non-locals have no appreciation for the historic values, but it is definitely different in both amount and in kind. It's not part of the culture they grew up with and that surrounds them, and they don't have cultural institutions and connections that remind them of other club's proud histories and rivalries that burned 60 years ago, waned, waxed, waned again and so on. You aren't surrounded by the local culture of the team and its fanbase with clubs and groups going back decades and generations, and your great-great-uncle hated my great-great-grandfather, because they grew up in different parts of town or belonged to different unions or churches, but they both maybe supported the same team. Because of all these differences the power of tradition is weaker.
Now all the fans that Man United and similar teams made in other continents (including here) in the 90s and 00s when they won constantly have much less of an emotional attachment to all that. It's real, but also less real. And the question: "why the hell isn't Man United or Roma or (if it ever comes to it PSG or Bayern or Real Madrid) in Champions League this year?" overrides all that completely. And they buy fewer jerseys and everything else associated with the team and they don't watch the UCL matches with Atalanta in the same numbers and their allegiances might even be fluid and changeable in a way that a local would never consider. And yes, there are counter examples. Clearly this forum likes things the way they are. There are millions of fans and you'll find every opinion and preference represented, but the forces pull mainly in one direction.
Further, the UCL itself will prefer a closed system for all the same reasons. Marketing to Africa, Asia and the Americas is easier when you can rely on those massive fanbases that the giant clubs built for themselves instead of convincing people they should watch Leicester who had a magical run then became pretty pedestrian their UCL year.
It's like how blockbuster Hollywood movies aren't made primarily for Americans anymore. The preferences of the worldwide customers do not align with those of the locals who invented the product, and so the product changes. There is a lot of pressure moving UCL to a mostly closed system. There will be fan resistance mostly in Europe, but I predict they lose, though I won't predict when. There is some, but much less pressure on the top national leagues to close as well, and there local preferences and their powers are bigger, though not unassailable. I'd put the odds of them closing eventually, some ways away, at unlikely, or many decades out, but not shocking if it does happen sooner.
ETA: Another point re the foreign fanbases, there might be surveys showing they don't want these changes either. But there are stated preferences and revealed preferences. Many fans will say they want UCL to stay the same, and believe it honestly, but they still won't buy or watch as much when their team fails to qualify.