Yes, the catalogue is deep, but much of it consists of dead horses that have been beaten for years or once-great icons that were mismanaged into relative irrelevance.
Budget constraints didn't seem to be what was holding them back before, and I can't see Microsoft suddenly managing the IP any better than Activision were (if anything, I can see it going downhill faster).
Those along with not clogging up the candy crush money printer will get them plenty of runway to really dig in and fix the culture.
It is sort of like if Valve actually made Half Life 3 now, most gamers don't even know what Half Life is, let alone why Half Life 3 would be such a big deal outside of being a meme.
Through that lense ActiBlizz is a great buy. Candy Crush and COD and Warcraft.
You don't need the top seller if your goal is to keep customers above the subscription cancellation threshold.
Not to mention these are lore-rich well-known universes and could result in multimedia franchises
Video games are very distributed. Its the work of a system of people, from high level concept artists building a shared mindspace for how the game should feel, to writers, to gameplay programmers, low level engine developers making the previously impossible possible, and at the bleeding edge sometimes even hardware engineers. All integral to the process.
Very, very rarely a "10x leader" will emerge from the industry. Someone like Chris Metzen of Blizzard, or Martin O'Donnell of Bungie, or John Carmack, Tim Sweeny, Peter Molyneux (for all his flaws lol) or Todd Howard, Miyamoto, or Kojima.
But its nowhere near the level of impact on the final product that a talented director or writer of a movie can bring to the table. Even as recently as the Bobba Fett series, and Tik Tok blowing up about the two episodes Bryce Dallas Howard directed being significantly better than the rest of the series. That just doesn't happen in games. Games don't "bring in" "guest directors" to... produce... one installment? One segment of the overall game? Its just nonsense. Moreover, every great leader I listed above, eventually, produces something kinda shit. Even the stuff they're known for, oftentimes they'd say that they received far more credit than they deserve; that the team deserves far more than they get.
The broader conclusion being: it takes some literal magic to produce great games. Ask anyone in the industry and they'll all agree: its a miracle games ever ship, let alone that some stand among the highest tier of art humanity has ever made. You can't just buy cool IP, like a sugar trap to attract talent like they're flies. On the contrary, the one model which does seem to work, is the literal antithesis of the Disney model: teams which work together for abnormally long periods of time (5+ years) trend toward producing fantastic stuff, eventually.
Though to be clear: there's something about that "Disney of Games" idea that I find fascinating as an explanation for Microsoft's behavior. And while I disagree with the assertion that it will work, I can't disagree with the guess that its a model Xbox has used, internally, to talk about their growing portfolio.