It's my understandiing that a lot of schools have been holding onto their Win7 images for dear life. Things are going to get interesting soon, and by that, I mean scary.

(I'm not as concerned for my own school, as we'll likely be converting computers too old for Win10 into Chromebooks.)

Microsoft 'Confirms' Windows 7 New Monthly Charge

https://www.forbes.com/sites/gordonkelly/2018/09/08/microsoft-windows-7-monthly-charge-windows-10-free-upgrade-cost/