Saw this on the Daily Star. http://www.dailystar.co.uk/tech/news/583111/Samsung-Galaxy-S7-Android-Nougat-update-7-why-no-upgrade I've been waiting as patiently as I can to receive Android 7 on my Samsung Galaxy S7. I'm on AT&T, so I really had no hope from the beginning.
Samsung is finally pushing the update to S7's globally. However, if a device was purchased through a mobile carrier and not directly from Samsung the wait is still on.
You could go the route on XDA and flash it to your device. Many people are having success with that. While others are noticing high battery drain. I started to go that route but decided against it last minute. Here is what I did instead and I'm actually loving it.
I haven't used Nova Launcher in years. Android Authority has a great write up on how to have a very responsive Android Nougat launcher look alike. No flashing required.
This will hold me over for now... But if you can't wait and want to have fun go here at your own risk:
Otherwise ATT should have this update for us within a month fingers crossed. Once Samsung has an update the carrier's have to test it before they can release it to their customers. After all if something were to go insanely wrong with the update the back lash would be aimed at the carrier's. Many people like myself maintain their business with their phones. So I understand the caution. Just wish they moved a little faster.