I have a Surface Book and I will vouch for how awesome the 3:2 display is. I agree that 16:9 is a bit disappointing. It's the lingering dominion of HD televisions converging on computing. I am glad that some companies are re-asserting the unique needs of computing and adjusting monitors accordingly.
This hasn't been true since the Retina screens came out. One of the reasons I was sad to "upgrade" to the new MBP from my 2012 model was losing the 16:10 display.
Untrue - my MBPr has a bunch of display options, most of them are native 16:10. You may want to hold off on the upgrade for other reasons, but display ratio shouldn't be one of them.