Sadly the headphone jack is definitely dead.
> They have to keep catering to every possible audience
That's not Microsoft's job at this point, they heavily invest and push the envelop where makers don't want to take the risk, but from there it's for Lenovo, Dell, HP, Asus etc. to decide what they want to market and which chip to push. The same way some of them put weight behind AMD while other went full Intel 100% of the time.
Everything that has tried to go or is going against that tide either failed (eg: Itanium, Windows RT) or never had market share to lose in the first place (eg: MacOS, Linux in the consumer space).
Microsoft would be stupid to be "courageous" and drop backwards compatibility, that would even trump Apple's courage abandoning the headphone jack. It also makes business sense to keep your eggs in multiple baskets, assuming those baskets are each commercially viable.