UPDATE after hearing from CS
Emailed CS yesterday and had a response this morning. Unfortunately missed the boat completely.
Response summary:
Sorry didn't get the upgrade
Next FIVE paragraphs explain upgrade policy and order
Thanks for flying delta
Not that I expect to hear back, but did send a quick reply explaining that inwasnt concerned about losing a first class seat on a specific flight. I was concerned about losing ANY seat on ANY flight
Will see if there's another response