This looks to me like a lot of the failed airline mergers of the 80s and 90s. Two sick companies merging to form a new larger sick company.
AT&T owns CNN, the third player in a two team league; its various "general rerun" channels the main two of which are in deep in big $$ contracts with the NCAA, NBA, and NHL for what is, just about, the only non-rerun content on them; its HBO and Cinemax channels; DC comics; 50% of the CW network; and, after approval, still the majority of DirecTV. IMHO, the value of linear "general rerun" channels, is declining very fast, as the same sort of material is available free on OTA diginets and on free streamers like STIRR and Pluto, as well as being tossed in with the new original stuff in the major streaming services. Linear HBO is really just for people without internet nowadays.
Discovery owns 20 US channels, 17 of them in English, all of which are pretty much remixs and variations on each other. Much similar material is also available on OTA diginets, and, bluntly, a lot of self-appointed YouTubers produce similar material.