I reached out via Twitter @applesupport. Awaiting a reply since it's after hours. Can't even get an appointment at the Genius Bar until Sunday after 6PM in most Apple stores around NYC. The 24 hour apple store in Manhattan has no availability even in the middle of the night. I gotta wait til 1AM Monday morning to go.
It happened to me again tonight. I am now running iOS 10.1 (beta) and was using waze for traffic and hazards on my ride home from work, and after 5 mins it knocked off to "no service." I do not understand where these forum sites are reporting it's stuck after using airplane mode. It happens out of nowhere, but it's happening more with waze, I can't speak for other navi apps as I only use one.
I do use the phone with Map my Ride which is a GPS based app, and the recording doesn't go out with that. I don't understand the coorelation between Waze and iPhone 7. This wasn't happening with iOS 10 on a 6+ in beta and final release.
Running:
Verizon iPhone 7+ w/ iOS 10.1 (problems same on 10.0.1 previously)
VoLTE is running.
Attempted:
Wiped Phone Clean and Restored from iCloud Backup.
Reset Network settings x100
VoLTE being off didn't seem to do anything.