For what it's worth, the Acer Liquid M330 also stopped getting updates after the initial Anniversary Update release. In that case it was due to some showstopping usability bugs. In fact, Microsoft eventually even clawed back the roll out of the initial AU update after a day or so, leaving some users stuck on Threshold 2.
With build 14393.321, the bugs that were affecting the Liquid M330 were resolved, and the latest build is again available for all Liquid M330s.
The moral of this story is, the Anniversary Update has had a rocky start that led to a halt of distribution on at least one other 3rd party device as well, but the issues were resolved and distribution re-started.