.. in that link he says only the italicized parts are things he hasn't said
The page is confusing: the marked parts are the ones containing confusing/inaccurate statements. I don't think this means that the other parts are verbatim quotes.
there are some parts at least that sound pretty similar
the whole system is basically GNU with Linux added, or GNU/Linux. All the so-called “Linux” distributions are really distributions of GNU/Linux.
Whether you use GNU/Linux or not, please don't confuse the public by using the name “Linux” ambiguously. Linux is the kernel, one of the essential major components of the system. The system as a whole is basically the GNU system, with Linux added. When you're talking about this combination, please call it “GNU/Linux.”
I think everything points to stallman being more worried about the factual errors in the quote (rather than the qualities that make the quote funny)
When did Stallmann actually say that line?
He didn't. He did respond to it though: https://www.gnu.org/gnu/incorrect-quotation.en.html
.. in that link he says only the italicized parts are things he hasn't said
The page is confusing: the marked parts are the ones containing confusing/inaccurate statements. I don't think this means that the other parts are verbatim quotes.
https://www.gnu.org/gnu/linux-and-gnu.html
Sounds very different, too.
there are some parts at least that sound pretty similar
I think everything points to stallman being more worried about the factual errors in the quote (rather than the qualities that make the quote funny)