Ever notice that they sometimes don't give silver medalion the open delta comfort sears even though I am first on the list and it says that i am number one for upgrade on the delta app?

I then scan boarding pass. It spits out a ticket.
The agent tells me i have a seat change.
The seat is the same non-upgraded seat that is om the app.
i board and see multiple open seats in delta confort.
I recheck the app and the upgrade list now says zero seats available.

While i cant prove the person sitting in the open seats will be nonrev, i highly suspect it.