Upgrade preserved during SDC?
 

Todsy I was trying to SDC a ticket I had upgraded with cash from Y after booking, and to my surprise after the ticket was reissued I was able to immediately select seats in the first class cabin. Reservation shows C fare class and not OU which seems to indicate it was not an immediate complimentary upgrade. I was under the impression that all upgrades were lost on voluntary changes (and indeed a previous agent told me as such). Was this just an agent error in my favor? Happened over text messaging support if that changes anything.

you technically didn’t “upgrade”- you paid a fare difference and had the ticket reissued (hence the revenue fare-class of “C”, not “OU”). COMPLIMENTARY upgrades ARE lost.

Also, AFAIK so are the upgrades where you pay to upgrade your seat on a segment. Those are supposedly nonrefundable too, although DL agents have been known to make exceptions.

OP is lucky that the purchased upgrade was the sort that involved upfaring to a FC ticket (which also allowed an easy SDC into any open FC seat with no fare class availability requirement).

The OP didn't get an "upgrade". He paid the difference to change a Y fare to a C fare. Whether this happened at the time of booking or after the Y fare was actually ticketed is unclear. If it happened during the booking process, then no re-issue was needed.

OP says that the ticket was upgraded with cash after booking.

Yes it was upgraded via the app offer - I did not pay a fare difference. Receipt still reflects the original fare class of L so I didn't think this was an upfare. Only the "my trip" screen shows fare class C.

Yeah so I thought I did purchase a segment upgrade. Agent also gave me SDC options only for the flights where my fare bucket was available.