I don't agree with this at all.
As far as I am concerned, the fewer accounts needed the better. You can't keep batting people to a different forum because they happen to have raised a point in the "wrong place". Look how well that worked with trying to get people not to post feature requests as GitHub issues.
Personally I feel that keeping Discourse (self-hosted or otherwise) would be better as there is an awful lot of information contained here.
Otherwise consolidating everything under GitHub sounds interesting.
"One login to bring them all and in the darkness bind them"