After Fox merges with Disney (which unless something changes seems likely to get government approval soon), what happens next? What will companies like Comcast, Viacom, Netflix, et cetera do to compete? Will any media companies go defunct?
My personal opinion is Comcast will try to buy Viacom or Netflix since they won't be able to get Fox. They might seek some smaller companies as well, but to compete with Disney they need the kind of scale that only certain companies can give. A Verizon/Comcast merger attempt may not be out of the question either. I'm not sure regulators would allow it, but it might be in the interests of both companies to merge together. If Verizon doesn't go after Comcast, they might try to buy National Amusements or they may just go after CBS and/or Viacom as individual companies. Because AT&T now owns WarnerMedia, Verizon needs a media company with some scale to compete. Smaller companies like Sony, CBS, Lionsgate, MGM, AMC Networks, and even Viacom will need to either attach themselves to larger companies or merge together to compete with Disney, Comcast, AT&T, and Netflix. AT&T's WarnerMedia may try to buy MGM because they already own MGM's pre-1986 library and MGM would give them more scale to compete with Disney and Comcast. While a CBS/Viacom remerger seem less and less likely, CBS may still try to acquire Paramount and Nickelodeon from Viacom.
Disney will probably be required to sell off some of the properties it gets from Fox to be able to get government approval of the merger. Additionally, Disney may want to use some of the IPs it gets from Fox to make deals to get full rights to Spider-Man, Incredible Hulk, and other Marvel characters with rights issues and tie-ups or to make deals to acquire potentially lucrative franchises like Teenage Mutant Ninja Turtles. In the five to ten years, Disney may need to make another medium to large size acquisition, but for the time being, I'm only expecting smaller ones. The largest acquisition Disney may try to make is The Jim Henson Company because of various links to that company.