The below mentioned update did not fix it for me BUT I finally figured out a work around to keep all the functionality but still stop the battery drain/always on.
I went to the Android app store and downloaded GOOGLE CALENDAR app. Apparently the S7 calendar app is NOT the stock nougat calendar. I then turned of notification in the version of the calendar that comes with the S7. Default settings for the google calendar were fine, I didn't bother to configure everything and the notifies are still following the times set in the appointments in Exchange. You can override that in the google calendar if you want, or not if you are happy with that. Now when the notify occurs, it buzzes the phone (i usually leave my phone in vibrate, if audio was on it would chime), puts a tiny calendar icon in the always on display (I use my phone as a watch so I want to see the low-power always on), and keeps the notify led flashing until i swipe away the notify (or opening it by tapping it). It never turns on the screen. I assume if you turn off the always on display in nougat settings it just flashes the blue notify and buzzes without doing anything else.
At that point, you can choose to still manage all your appointments through the existing calendar app, or you can use the google one you just installed. You don't have to change anything with accounts or sync. And it works with multiple calendars syncing as normal (mine syncs with ms exchange).
The one difference is if you actually tap on the icon to open it, it will open in the google calendar. Still perfectly fine compared to a phone where the first meeting of the morning was knocking down my phone's battery and making it get hot in my pocket.