Thanks for Clarity on GUC Expirations
Zorak and bgriff's replies answered my questions. At least I know I was bitten by Delta instead of my own mistake. I had a GUC's from my 2020 Diamond qualification year that I used in the first half of 2022. Delta was great about resetting old GUC's, RUC's, and Ames companion certs to 1-31-2023 due to covid when I wasn't flying much. But now, the old certs and the 2022 ones all expire at the same time, which makes the second half of 2022 crunch time.
People complain about having to use two GUC's for in-advance upgrades into Delta One. That did not bother me because I use single GUC's on unpopular routes (example MAD) flying old planes (767's) for day of departure upgrades to Delta One.
I tend to re-qualify for Diamond late in the calendar year, so the change in GUC expiration is a real downgrade for me.