I was just siftin’ through Avalanche for the riffshots project and forgot that there’s a Numerosity joke in there. Does Sesame Street still use those at all? If not, that’s a riff that would fly over the heads of anyone born after, say, 1995.
But MST3K has always been really awesome about keeping riffs relatable to almost all the audience and then a few obscure ones that wink to those who know.