That is way too many studios for me to think about in a meaningful way. For most of them, I think I'd ask the head developers of each studio to submit some ideas, and then we'd discuss which ones would be the best fit for both the studio and Gamepass.
The two things that I think need the most immediate attention would be WoW and CoD though. For CoD, I think I'd have one team develop a really robust game engine, and then have other teams that would add new maps, weapons, etc... every few months. Essentially, it would be like getting some DLC every few months, but there wouldn't be a whole new game every year. I personally suspect that is what the CoD fanbase is looking for anyway is just new content to essentially the same old game. Maybe release a new game like every 3 years, but each game has like 6-10 DLC packs worth of content included free with Gamepass, spaced out evenly during those 3 years.
As for WoW, it actually used to be a bigger money maker than CoD, but it isn't nearly that big anymore. It is losing players fast. I'd see if I could get back as many of the developers as possible that developed the original game. Get them to fix what is wrong with WoW and get the fan base back. The main problem with WoW is that the fans no longer have any faith in it. However, with Microsoft buying them, that is a chance for them to win back the trust of the fans. Each time there is new content, it needs to be tested so that it is fun and polished before it's released.