I was trying to make an analogy fit, but can't think of a good one, so the problem I have with MS strategy is, it appears that they know that they can't just leave mobile behind. Their future depends on it, because while there still is use of windows, this will just decline as time goes on. For how most private consumers use computers, cheap android or ipads will do the job. The problem in allowing this to happen is, eventually commercial will catch up as well, and they'll make inroads to that sector as well, like they already are.
The surface line has probably done much to fend it off somewhat, offering windows tablets, but apps still lag behind and the surface devices rely too heavily on full windows, to the point that UWP and what not hasn't really done much. Sounded good, but didn't work...
In retrenching mobile, my thinking is that they're just letting the platform die off, and realistically, any future reboot is going to be so far behind, as a result, that I can't see how it will take off in the first place, unless MS' plans for a future reboot are also very uncertain.
I can see that the industry is working on newer tech. Bending screens, are one of them, the problem is, smartphones offered brand new functionality which dumb phones didn't really offer as well as maintaining all the dumb phone functions, so they were coming into a new space. Any of this stuff such as folding screens, it's not a major change, and where MS are really stuffed is, any reboot still won't provide that third party support that users will expect when they get their new category.
This is why surface RT failed, there was no new functionality, due to a lack of apps, meanwhile, a lot of the functionality users could get from a laptop wasn't there because it didn't support win32. Even with the success of the surface pro, if they released RT again today, it would still fail.