Why would they?
edit: "Old school people" don't "miss" convenience, they would love convenience. Instead they have standards and platforms that are sabotaged or abandoned when convenient by companied building lock-in. What we get was built by people in their spare time, or chiseled out of academic funding, and though it often sucks we should be thankful for it.
I think the chance that anything on Discord will exist in 10 years is probably about 2%. If Discord exists (25%?), they'll have blanket deleted old data multiple times by then. Not that it matters much, because finding anything old on Discord is impossible anyway.