On a recent domestic flight (ORD-LAX last week) I got an upgrade offer (as a Platinum with around 100k Loyalty Points) several days before the flight, and my wife (EP with 250k LPs) on a separate reservation did not. Both reservations had two people total. Even when we pulled up the reservations on the app, I had a chance to upgrade and she had no offer at all. One of the four of us really needed the upgrade due to age/mobility concerns so I bought the upgrade I was offered and gave the seat to that person rather than take the chance that her free upgrade wouldn't clear. Strangely, she was never offered a buy-up upgrade even though her status is higher and the fares we paid were the same. She narrowly missed getting a free upgrade for herself and companion. In retrospect, my purchase might have closed her out but we didn't want to take that risk. On the return flight (LAX-ORD) the companion who needed to be in first was not with us. Neither of us received an upgrade offer and neither of us got a free upgrade (she missed by 4 and I missed by 7).

Curious whether the algorithm for upgrade offers typically works that way. Seemed like having lower status actually worked in my favor because at least I got the offer to upgrade for a reasonable price.