Thanks for all the responses - very helpful. While I really wanted to fly PP, it was opportunistic and not that important to me. It's SFO-EWR and the scheduled arrival time is more of a factor for me. I'm mostly annoyed that I have to work now to get a refund.

Amazingly, I just saw that United called and left a voicemail - an actual human, not a recording, advising that because of the equipment swap they assigned me a new seat and that I will receive compensation at the airport. That's a first for me.

We'll see how it plays out.