You should ask, why now? Before they didn't care about it even a bit. The only reason I see is competition threat that they now see in Steam Machines. Competition is the only thing that makes MS do something good.

I don't get what you're saying. That's like saying that when people go to a store they need to make sure they get an Xbox One game and not an Xbox 360 one or PS4 one. Since people seem capable of managing this, I don't think that they'd have any problem managing the new markings. Since Xbox 360 compatibility is also considered a good update to the Xbox One, far as I know, and that requires actual looking at a web page to find out compatibility, I think that the "OMG, people will have to have an understanding of about the level they have now" a little overboard.

And yes, I do think that Microsoft is just talking about a shorter cycle or a maximum of one optional hardware variation per cycle, not something in the style of PC variation. The latter doesn't make sense.