It's called airwalking and to my knowledge vipeazone has found and posted numerous videos and even whole skips using it among other things.
He is a known glitch hunter by trade and occasionally speedruns, check out his stuff I'm sure many runners will learn a thing or two from him.
While airwalking was first made known by vipeazone I haven't seen a video of the oob in the spot I've shown in the op, I myself have learned the arwalking glitch from his videos, still there are possibilities with the glitch that he might not know about or didn't post yet.
Very truse, I did talk to him awhile ago and said he was investigation some more stuff, he has been actually more involved with trying to find possible routing for various things so there still stuff out there.
