I happened to notice an account (link removed) shown as suspended until the nonsensical date of “Mar 18 '92 at 16:28“? I am not asking why the account is suspended, but why the “until” date is 27 years in the past.
It's a '92 in the future, not in the past.
Suspensions longer than one year, or coordinated across sites, come from SE employees; the elected diamond moderators can only suspend up to a year. That particular user was at some point suspended for 99999 days, until the year 2292. The number of users network-wide with suspensions longer than ten years is very small, so there's no compelling reason to rewrite the date-display code to sometimes show a century digit.