Hey, Ray Reh.  Good find on the geohub because that was indeed a major source.  And you are correct that they are seemingly temporarily removed from display (I actually think it was a glitch, but I haven't tried reporting it yet).  But the 5-digit names do appear elsewhere at the city and even the geohub still has them in the KMZ files, etc.  I'm linking here to your example alley, https://x3mo.net/LOS-ANGELES-ALLEY-80875    There's been discussion elsewhere at OSM about all this and the consensus seems to be that the 5-digit numbers are the best choice (as opposed to that 10-digit number that nobody has really figured out).  And I've referenced the 5-digit numbers in L.A. city permits (I'm a feature film & TV location manager) and they were properly recognized there.   :-)
Cheers!    ---- Scott