They are limited a bit in pulling Windows 7 due to corporation use or they'd have probably done more to push users on already - we only just finally ditched Windows ME entirely so 7 isn't going anywhere for a little while. I'm not sure the entire details as it isn't my role but they tried deploying 10 twice at work and had to pull it due to issues one being the amount of integration with epos/embedded systems and Windows 10 even the versions intended for that role are kind of tragic and caused a lot of downtime - they actually ended up changing all those over to arch linux or something as it integrated ok with 7, didn't interfere with the intended usage and they needed to update them all.