I work at a co-location for Verizon based carrier termination services and in the same facility we have our switch Verizon has the servers that push out the data packers for OTA's and I own a VZW HTC M8, anytime any updates were pushed out to this particluar phone along with my co-workers LG G3 usually this server has anywhere from 200k-500k sessions running when OTA is being rolled out and dies down at around the 3 week mark. I haven't noticed any movement in those sessions and was running on normal tier 3 data packets up until about 10 minutes from writing this when the sessions jumped to 490k. All this meaning Verizon is pushing data to there OTA server only now, which means the initial roll out is imminent but has not started yet.
Take this with a grain of salt being I do not 100% have access to the data packets so this is a educated guess from experience. Same exact thing happened when my M8 got the "eye experience" update and that pushed the following day to my phone.
Hope this helps people understand the state of where there OTA is