This is a real thing, like
but I think the better way OGS has approached it has been with a hide ranks feature (which might not be widely known), rather than removing ranked games vs humans 
I think the reason a server like Fox could potentially have less of a OGA than say OGS is like the caveat to the fact that ranks adjust quickly on OGS. When you loss a game you immediately lose rating points, and more when it’s a bigger upset, so people will potentially feel that game to game on OGS.
On something like Fox, I expect it to be more so the critical promotion/demotion games that might cause some anxiety like if you’re within a couple of wins of a rank up or double rank up streak, or similarly on a losing streak to rank down or double rank down. But generally game to game it doesn’t matter as much.
But there can be other factors too than just the rank, like the time settings you play that can factor in.
Not a direct comment on this, but kind of an observed behaviour from streams. I think when someone might suspect opponents can be likely to use AI, on Fox (but presumably on OGS too), one might check the players win history before playing the game. If it’s all wins, or specific to Fox that they recently ranked up, you might see people avoiding playing that opponent and cancelling the game.
I wouldn’t necessarily want to encourage that sort of thing by making a win streak counter visible (imagine on the player name card), as we might see a rise in game cancellations. It’s more of an observation on how people’s behaviour can adapt to the current situation on a server when they’re motivated to play games regardless.