To pivot the discussion somewhere else, I'm not sure if this has already been addressed in this thread, but if MS were to make a handheld device should it be a locked xbox portable? Or rather should it be a windows based device?
There are a lot of advantages for going the windows route. For one the issue of getting developers to actually support the machine goes out the window. It will just run everything assuming the specs are high enough to run the game on it's lowest settings. MS could even do something like Geforce Experience does where it automatically sets a games graphics settings based on your GPU, so MS could create recommended settings for every title that is automatically applied when you launch the game.
The disadvantage if of course that it isn't locked to the Xbox ecosystem so users could purchase titles that MS doesn't get any return on. The advantage is a more versatile customisable device for those that wish to and access to an absolutely huge library of games and no need for direct support from developers. If it runs on Windows it'll run on that.
Of course at this point it's basically just a Microsoft branded Steam Deck. However it would run Windows out of the box, customised for a user friendly experience which supports GP.
MS may need to price such a device higher as they couldn't rely as much on a return via software sales but I think it would be a much better device overall.