An additional confusing factor is one-time, there was general inheritance of status even on same PNR, but that ended in 2015 where UA explicitly stated it would no longer happen.
2015 MileagePlus Change-No more inherited benefits from higher status accounts I used this inherited status to get E+ access for my kids an award tickets I purchased with my miles but did not travel with them, that ended in 2015
That was true for upgrade requests but I did most award tickets.

The GS benefit is more nuance as GS supported upgrades use a different fare class, PN (now), and that provides the higher priority. The off PNR otherwise does not get any other GS benefit unless traveling with the GS.