I dunno, it's not exactly a new phrase and I strongly doubt it's a surreptitious attack on progressives. The latter seems a bit much.
I'm speaking specifically to its usage in gaming culture.
That is a bold claim, do you think that every time it is used the person using it is consciously trying to exclude women?
They aren't referring to themselves as men, they are referring to themselves as the group "guys" which is non-gendered.
I think at it's core, it began as an exclusionary tactic to reinforce the boys club mentality of gaming culture. And its proliferation and popularity seemed to be in the larger twitch streams that share a lot of similarities with the anti-SJW 4chan/KiA sect, like in Forsen's stream.
Do I think every time Ninja uses it he's making a conscious effort to buoy that line of thinking? Not really. Subconsciously? Absolutely.