I saw this earlier this week when using a companion award ticket for my wife. At OLCI, I checked myself in first and it asked if I wanted to request an upgrade. I clicked that I did and ended up with an upgrade (for me only) from ATL to MIA.
On the return trip I would also have gotten an upgrade from MIA to JFK if the flight hadn't ended up being cancelled (though I did get a pre-cancellation beverage)

Lost the upgrade on the rebooking but hadn't been expecting it anyway so enjoyed what I could get.
With my wife being much shorter than I am and actually comfortable in coach seats, she insisted I take the upgrade. And after 30 years of marriage, I do try to listen to her, lol