I hope they will let it go, but if they see an opportunity to sue, they will.
Not to mention that they could change a few things in their toolchain or direct x to make proton's like difficult...
It is necessary to kick off SteamOS, but in I’d guess they are betting on capturing market share with their devices and OS, so that developers will put in the time to do Linux ports.
Proton is always a catch-up game and can’t seem to be the end-all solution.
And plenty of Linux ports of games don't work on modern Linux anymore because of dependencies. See https://news.ycombinator.com/item?id=30490570 from just this week.
It is. This is just fear mongering.
I can't think of a good reason why Microsoft would want to get in the way, here. Maybe if Windows was a major revenue stream for them, but they make most of that money through OEM licensing and the Deck is very unlikely to cut very deeply into gaming laptop or PC sales.
Beyond that, maybe Microsoft might view the Deck as a competitor to XBox itself, but the Deck is just such a niche product targeting different audience/use case that I don't see why they'd do anything anti-competitive to get in the way. It simply isn't worth the trouble.
Frankly, this just smells of anti-Microsoft sentiment that dates back to the 90s and early 2000s. But Microsoft is a very different company today.
Besides, in the absolute worst case (which I truly don't believe would ever happen), Valve could just start shipping Windows on these things.
That alone makes Steam Deck a non starter for me. Microsoft doesn't care about a tiny niche.