The internet makes it possible for people to get any "in" joke now and those kinds of oldie references have actually gotten kind of popular.
Not all in-jokes as some would rely on kids immersing themselves in an adult online subculture that is far from kid-friendly
But I get your point.
And I also agree with you that nostalgia is a big factor in some things aging better than others. Like, people thought the rainbow unicorn trend would have died by now but it's only getting stronger. Demand for pastel pony stuff will be around for a long while to come and these cartoons will get reruns, the toys popping up at yard sales and fleamarkets.
Kinda like Keypers, Lady Lovely Locks or Moondreamers is still huge with people who like cute and kitschy stuff, despite its age and never getting a popular reboot.