that would be up to HTC. All versions including international version doesn't have it. I think it's more than the driver. if it was the driver the root community would have already enabled it with a custom kernel
I'd like to report that I am having No Problems whatsoever with my HTC 10
The radio is superb, I am able to latch on to weak LTE signals that I could not do with my Note 4!
The Marshmallow version here is also the most robust Android I've ever experienced.
Also a great selection of free themes and tones from HTC!
I just have group SMS problems(for certain groups) and no RCS but I don't mind waiting for them.