Excellent summary of the situation. Agreed on every point.
My frustrations and distrust of MS are just that - mine based on my experiences which are heavily colored by being a software developer. Having "grown up" programming in DOS and later Windows environments I simply much prefer to program in a Linux/POSIX environment. That gets into a whole host of reasons - a mix of technical and personal preferences - that aren't really appropriate here.
I'll make a prediction. 5 years from now I'll bet I don't even have any thumb drives in my desk drawer, and no exFat file systems anywhere to be found on my systems. I did use a thumb drive yesterday - I put a couple dozen movies on it in preparation for a trip. I could have loaded them directly on my Chromebook, but space is limited on that and I haven't gotten around to putting a high capacity microSD card in it. Prior to yesterday, I literally cannot remember the last time I used a thumb drive. I know last winter I updated the music on the thumb drive for my car. That may have been the last time - 9 months or so ago. That's really why I have a hard time attaching any nefarious motives to MS's move - I think they, like me, see the writing on the wall, exFat's importance is on the way out.