I think the thing to remember is that standard ticket restrictions which go back to Pre-Civil War airline travel , is that the shelf life of a ticket was one year from the date of original issue. Of course there were exceptions and waivers and favors. The airlines were more lenient during Covid so that people would book without fear of losing their money. Delta, specifically, seems to have difficulty keeping this consistent (based on comments above). Delta.com may not be able to track original issue dates or phone agents may make a mistake. My guess is that Delta will eventually get this fixed and extending validity on a ticket will be more uniform. Anytime you get an extension, assume you are getting a freebie. I would not assume this would continue indefinitely. Loopholes will eventually go away as automation catches up.