Seems like the issue is chainstay clearance near the BB for big tires, so they went to wider crank spacing to accomplish chainring clearance around the wider chainstays. That made a wider hub necessary.

Seems like spacing the crank out is no big deal, but fixed gear wide hubs are a problem you can't fix with a longer axle. There are at least two acceptable hubs right now - what is it that you are concerned about?

The other way to go is to just go single speed instead of fixed and then you can use a common cassette hub. That somewhat future-proofs the frame.