How much sway do the affiliates have now versus back in the day?
Who knows. Sinclair owns entirely too many ABC stations. (Why, it's almost like there should be a law that limits the number of...wait...<checks earpiece>....oh.)
But consider Seattle: Let's say Disney could and DID pull ABC affiliation from Sinclair, just hypothetically. Who serves Seattle as the ABC affiliate now? KONG? They're Tegna-gonna-be-Nexstar, that's no better. KSTW? Uh, maybe, though as a CBS O&O that would be a little weird. KZJO is a FOX O&O so weird for the same reasons. That leaves KFFV, channel 44 (and right now you're saying "TIL channel 44 in Seattle is a thing!"), which right now is hosting seven Weigel Broadcasting digital subchannels.
Aren't duopolies fun!