You can crouch-jump up to a piece of exterior molding that gives you access to all of the balconies on one side of the street that runs between the B objectives in both Push directions:
This should have been fixed with update 1.4. Can you try again to see if you still experience this issue?
Hah, that wasn't me in the video--I don't do glitch spots. I'll see if I can get up there though and let you know.
@chaton, I played a couple of matches on Summit and was not able to climb up the broken wall to get to the first platform on the route to those balconies. Looks like it's fixed (though I'm not particularly good at crouch-jumping up things).