It's interesting to me that we've had this discussion before, with each edition change. We have literally had the same arguments made. I'm not sure how many people are here from, say, the 3.0 -->3.5 era, but the same discussion happened.
Are you going to be able to pick up your 5.0 PHB and create characters for OneD&D? Most likely not, but what is your expectation about that? When a new PHB comes out, I suspect that people playing D&D will adopt it. All the material is in place for a Pathfinder-esque game for those who don't want to adopt it.