firefox messes up their DNS filtering, chrome doesn't. so they remove firefox and enforce chrome. if you see that as a slippery slope, you're imagining it. they probably 1) have a decent app like ninite to remove and install apps, 2) don't have anything but their production environment, 3) don't have a homogenous environment in terms of patching (maybe they do), 4) don't have people to go around and make sure the config changes they push (however they would push them) took, worked, etc. so they block the app. maybe eventually they reinstall it. welcome to IT.
...which reinforces my point about how people actually doing this and people speculating about it tend to respond to issues like this.