I vote for "quotemanteau" to be officially sanctioned! But I would say the specific case is merely a snowclone[0] of "any sufficiently X is indistinguishable from Y"

[0] https://en.wikipedia.org/wiki/Snowclone

It appears to have the properties of both in this case.

That is to say it's a snowclone where the substitutions come from another quote.

I guess quotemanteaus are a special kind of unique snowclone.

You could take "with great power comes great responsibility" and form the snowclone "with great X comes great Y" and then take the quote "the medium is the message" and use those in your snowclone to make the quotemanteau "with a great medium comes a great message"

Hmm... I feel like I should try concoct more of these. They're fun.