I tried to see if there was any threads posted about the recent change to GWX and I wasn't able to find any. Anyways, recently they changed the way GWX works. Now, GWX sets you up for an upgrade date and if you leave your computer on then it will start updating. The close on the x box doesn't do anything because the upgrade is already scheduled. So you have to actually read what it says and click a few buttons to unschedule the upgrade. I'm sure there might be a few ways to stop the upgrade process if it begins to happen (haven't looked into it) but it has apparently pissed off a few customers that left their computers running and came back to Windows 10.
Seems like Microsoft will do anything to try to get to the 1 billion downloads. I for one have deleted the KB3035583 (GWX) patch only to find it back on my machine and that is with me not updating any updates since taking it off (deleted again). They state they will stop bothering you in July about updating but this latest tactic is a low blow. If people haven't upgraded even with you putting the GWX in criticial updates to try and ensure everyone gets a message everytime they boot up your PC or every few hours the shitty program runs then they probably don't want Windows 10.
Here is a link to an article about it and there are a decent amount of pissed off people in the comments section.