Arguably so, but all I can find are other plagiarized copies. :-P

The New Yorker's paywall has successfully obscured the origin of the joke, so that's on them, as far as I'm concerned.

"It's from the New Yorker. The most important magazine of our time. Probably the most important magazine that ever was."

(From a vaguely-remembered 1990s-era ad campaign that I thought was excruciatingly self-indulgent at the time, but which evidently worked.)