Decades of experience in the USA indicate that no matter how popular soccer is internationally, the locals in the USA don't care. See also to a much lesser extent, nascar vs F1.
In the short to medium term I don't think the business entity known as ESPN or MLB can survive USA cutting the cable cord. You're probably correct that someone is going to buy most of the pieces at the bankruptcy auction and probably right for example that baseball will be popular in Japan and central america yet that won't matter for folks in the USA who will not be watching.
No one in England is going to stop watching Manchester United games to start watching Chicago Blackhawks games, or even to watch some sucky MLS game. That's not happening man. Get that out of your head.
No one in China, Europe, the MidEast or Brazil is gonna stop watching basketball and start watching some sucky hockey game. That ain't happening either.
Do you have any idea the YoY revenue growth global sports leagues like PL or the NBA enjoy at the moment?
What you are saying may happen, MIGHT happen in your small neighborhood... though I doubt even that... but it certainly isn't gonna happen on a scale large enough to actually make the money that PL makes in a year. In fact, I doubt that American soccer and American hockey will even make the money something like the NBA pulls out of just China. Let alone global basketball in general.
Basically, you need cheap, accessible sports to challenge the global soccer and basketball behemoths. Something that could be played barefoot in a field. Or you need to JOIN the global soccer and basketball behemoths.
But yeah... sports leagues like American football, American hockey, or American soccer stand little to no chance of challenging those more global leagues growth wise. Best outcome for them would be to somehow link into those behemoths. And I can only see American soccer being able to do that... MAYBE?