Can they even determine "What's next?" very accurately though? I imagine the various teams are pushing out what they can, when they can, and don't even have a clear picture of timeline themselves. Callum isn't walking around the office with a notepad looking over people's shoulders and writing down what progress they've made (as far as I know they're still working from home anyway). It would take the devs a non-zero amount of time and effort to provide Callum with an outline of all the things they think might be coming soon.
Then what if they misjudge something and find a critical error that delays rollout? I can see the posts now haha: "They said perks were coming soon two patches ago and we still don't have them, how dare they!"
You're right, mexxico has been doing an awesome job discussing things he has first-hand knowledge of, but I've got to imagine it's really time consuming to read people's posts and write meaningful responses in return.