I can confirm this, as I just updated to 8.01.
No Cell Phone Service.
Beware
Ouch! Sorry to hear of your troubles. I’m waiting to update to iOS 8 for a month or two...
Getting ready to upgrade my Mac to 10.9, I feel it’s stable enough to run my Windows 7 via Parallels in.
Likely a winter project...
I’m a LONG way from updating to 10.10, maybe 2016...
Good luck!