In the sense that the rear end on the F900GS is completely different from the 900GSA, the 800GS, and the 3 outgoing models. Those 5 others still have the same wide pillion seat, grab handles, and racks for top box and panniers. F900GS seems more aimed at single rider off-roader use with the tiny bench seat appearing more useful for strapping a bag to.
If I can fit an 850GSA or a 900GSA in the gate I'm sorted, but it's tight enough for my 2015 F800GS as is.
That's why I was going for the F850GS...
Anyway of finding the fairing width online? All I can see show dimensions referring to width as the handlebars.