they’re gonna handle so many companies without a good track record of being able to do it. To make the money from King they will need to be able to retain talent and steward its properties properly.
No they don't. As we've already seen, MS doesn't have to do anything in regards to development. Promotion, marketing will get a boost but they can be hands off most of the technical details and still make bank. Bethesda, King and Activision are all quite profitable on their own. Now they simply can't develop for Sony and they get distributed on Game Pass day 1.
Also, exclusionary buy-outs are bad for the market and should not have been allowed. MS buying up huge game competitors and then restricting their choice on which platforms to develop for is clearly anti-competitive behavior.