That was part of why I allowed the update when I was ready for it. In both instances last year, I found the phone was updating on its own in the middle of the day and on the network. I'm told that you get a better update experience when you can keep the phone in one location while downloading the update, because it is possible to corrupt the download file when your connection switches between multiple cell towers. For that reason, I like to do updates when I'm stationary and on WiFi and connected to power. That and OS updates count against your data allowance on Verizon. This one is 1.2GB.
I also like to be able to properly backup my files before an update in the event that the update does not go as planned. I've found that I normally don't need the backup, but the few times that I have not made one are the times that I wanted it. I've not had issues in some time now -- they've gotten really pretty good at this.
I can't tell you which manufacturer's devices the updates get forced to, or if it happens to all of them. For me, it was the LG G4 and my wife's Galaxy Note 4. When I complained, I was told about the updates being forced so the pending updates can be sent. That was my experience. Yours may be different.
From my experience, you're going to at some point wind up with Nougat on your phone unless you are religious about refusing it daily. If you just ignore the update notification long enough, it'll probably happen unless you constantly say no. I ignored it. Big oops.
Better to plan for and do the update on your terms.