In the past year I have had two situations where I had a Y ticket (probably X/T) and when IROPS triggered the automated email/phone call, I logged into the app and discovered I was presented with five or six rebook options, several of which booked directly into F. I'm assuming these were routings where Y was sold-out.

In one case I went from PIT-LGA-MSY in Y (and way down on the upgrade list for both flights) to PIT-ATL-MSY in F (probably jumping a bunch of DMs, PMs and GMs in the process). The new routing also arrived an hour earlier.

In the other case I went from PIT-LGA-MCO in Y (and way down on the upgrade list for both flights) to the same routing, later flight LGA-MCO and rode up front the last segment. In this case I likely could have made the earlier connection, but for an hour I took the upgrade.

It seems that you can often weasel your way up front through IROPS. While this is good to know, DL's system should be sophisticated enough to do the following:
Pax 1 is FO on flight A, and is offered flight B because if IROPS. Pax 2 (1/x on the u/g list for flight B) gets u/ged to clear a spot in Y for Pax 1.

As it stands now, it seems like in the situation above, Pax 1 goes right into F and Pax 2 is now 1/(x-1) on the u/g list.

If three or four pax are rebooked into F, I can see how Pax 2 might perceive that Shena is in the house.