[anyfoo]

That seems to be the recent interpretation (or at least I only recently read about it, it seems to be a thing right now), but I remain unconvinced.

It's just entirely plausible to me that the pun was just a "happy accident", and the originator of the joke really did mean to give a groan-inducing borderline-tautological answer that does not offer any insight besides the obvious. You were expecting a punchline, but your expectation was subverted!

And at least that's also funnier than that lame pun. I'd be pretty disappointed to be honest, but we'll probably never really find out.