That scene to me closed out the Marlo chapter perfectly.
Marlo wanted the recognition. My name is my name!. But out on the streets he's already no one after taking a low profile for a little bit.
Meanwhile the corner boys are talking stories on how Omar went down surrounded by 8 or 9 guys for his final stand.
It's a close call too, a gun and a knife, and he didn't even see the knife until the end. The game is passing him by like it passed by many of the others before him.
But his face after the scene, and the fact he just left the reception early, shows he belongs there. His fate will most likely be a tragic death, but he didn't want to take the stringer approach and get out of the corners.