I live there. Still lots of VA 237 signage at the VA 120/237 Fairfax Dr. intersection, and on the relinquished route east of that intersection. Maybe VDOT was sloppy about not removing VA 237 signage on the roads turned over to Arlington County, and maybe it lacks authority to either remove the old signage on what are now county-controlled roads, or force the county to remove it. But VDOT still controls VA 120 and presumably can remove VA 237 signage thereon, once it gets off its ass and cleans up the signage.
VDOT could go farther, and put an End VA 237 sign assembly on Washington Blvd. at its intersection with VA 120. Not holding my breath on that one, either.