Real and Barca, albeit to a lesser extent, have sold, remortgaged and securitised everything conceivable, They have little by way of new venues of finance available. Real, I read recently, have 90,000+ members as well as a waiting list who pay an annual membership fee in the low hundreds of euro's (in addition to season tickets). This hasn't been increased in well over a decade and the club have always said it is off the agenda, it is considered politically toxic. They just increased it to much uproar. They sold ronaldo to avoid reporting an official loss last financial year and even changed the date of their financial year end to report following year income in the current year. Added to this, their basketball team loses a fortune (as does Barca's) and they have embarked on a very expensive refurb of their stadium and adjoining shopping mall. In short they need a new avenue of cash to devour. I get the sense these two are the main entities pushing this potentially along with US/Arab owners of clubs in other countries. In the background, I wouldn't be surprised to hear that Amazon are lurking as the exclusive streaming partner and that is the real cash cow here.
What that might do the future domestic league tv deals, we can speculate on. But it would have to feed through to club valuations, future discounted cash flows and so on that funding partners will look to when making a call as to the amount and interest rate of any debt. And with news of this filtering out recently, it would be remiss of a club planning a big stadium project to not pause and factor this into consideration.