I'm going to write my opinion about compare between Paramount-WBD and Disney-20th Century.
If antitrust law is enforced strictly, Paramount-WBD merger would be bluntly rejected by regulators since Disney-20th Century may get approved with some conditions like require Blue Sky Studios to be sold. Why? Disney is very weak with adult films, even Marvel and Lucasfilm aren't big enough. 20th Century enabled Disney to boost up with adult contents.
Paramount-WBD = debt spiral, heavy debt, higher interest rate, less new contents and more liabilities. Also, AOL and AT&T failed WB, so Ellison could end up fail WB again. The split wouldn't be nice nor smooth. There are many people dislike Ellison due to horrible histories with his dad. The cut would be extremely painful for both of Paramount and WBD. The clash would be super nasty and it can devalue the iconic brands.
Disney-20th Century = surprise issues due to pandemic, more debt but not extreme scale as Paramount-WBD, rocky start for Disney+ and closure of Blue Sky Studios. It got much better after pandemic ended and they recovered a lot that would be unlikely for Paramount-WBD. The clash is mild/moderate, especially with Pixar, Marvel and Lucasfilm.
Paramount-WBD is not most worrying for me, but my most worrying is about Ellison because of his dad and I just see Ellisons as evil. Zaslav is no better and neither is Bob Iger, so Ellison and Zaslav are worse than Bob Iger. Bob Iger will be gone soon and y'all have to worry about Ellisons.
Paramount-WBD may have new lessons for Disney to learn about which strategies work or not, also Disney could hire those people who got fired from Paramount or WB.
WB is too cursed, so curse could destroy the Ellisons' fortune and they would left with much less money like happened to Ted Turner, however unlike Ellisons, it wasn't Ted Turner's fault for lost the wealth, so it was on AOL.
I'm praying for Paramount-WBD to be BLOCKED PERMANENTLY, but it is unpredictable.