-- The stranded part of US 95, between I-11 and the US 93 business route, is included in the extended NV 172. OSM, and some discussion on the AARoads forum, indicate it's new route NV 173 (unclear whether it's signed), rather than part of NV 172.
Per recent discussion on the AARoads forum:
-- the stranded part of US 95 is officially NV 173, not NV 172
-- unclear whether NV 172 officially extends west of I-11 exit 2, despite what OSM says
-- in any case, as of last Sunday, no NV 172 signage west of I-11 exit 2, nor is there any NV 173 signage.
My inclination is to truncate NV 172 back to where it was originally (with a corrected endpoint at I-11(2)), and rename the NV172_S point on US93BusBou as Old US95. Also, to ignore NV 173 for now as unsigned. I expect to do a field check in October (en route to a college class reunion in the Bay Area), so all this can be revisited at that point or as other new information comes in.
Most of the NV 172 mileage I would truncate away is concurrent with US 93 Business, so it can be claimed that way.