So for anybody that was genuinely interested in hearing the finer details of the UWP and wanted MS to clarify on how open it is, I urge you to watch these two presentations from Build:
Particularly the first one. They should answer any question you have.
- Universal App Model Overview: Whats New in the UWP App Model
- Project Centennial: Bringing Existing Desktop Applications to the Universal Windows Platform
Judging from his Tweets, he's actually quite happy. Although for some reason he still wants "a clear Microsoft *commitment* to UWP being open in specific technical ways". I'm not sure how much clearer they can be when they say you can sign your app with any CA you want and distribute through whatever channel you want.
If he unequivocally said it was great he would look like an idiot since he threw a tantrum a month ago.