You're not wrong, but you may be reading it in the wrong tone. There is a certain type of joke where the punchline is something that was true for so long, it's

You're not wrong, but you may be reading it in the wrong tone. There is a certain type of joke where the punchline is something that was true for so long, it's acceptable to repeat it ironically as a sort of inside joke, knowing it is obviously not true any more. Best pulled off if you were actually there, of course. I think that's what's going on here.