So their highest priority is most likely not to deliver a 100% PHB-compliant 5E adaptation. It's not top of their list, and it never will be. They never claimed it was, and they never "lied" about it either, as some more vocal forum posters like to throw around. Quite the opposite: In the early days Swen even had mentioned in interviews that the attack roll / low HP system would feel like a hard sell to non-D&D players so they wanted to change it to a high HP / most attacks hit system, but apparently WotC had put their feet on the ground in that regard - because it would otherwise deviate too far from the published rules probably.
I would happily read that interview. Would you, endolex, or anyone else who reads this and know about that intervew, be kind enough to give me a link ? (Save that, if anybody remembers the journal or the time period in which this interview was published, I guess that could help me find it.)