Not if you don't process the information in the same way.

I said suggests, not proves. The point of the word "suggests" is precisely to acknowledge compactly that one can easily raise objections such as the one you raised.

Similarly, I'm pretty sure that I can process written words at a speed at which spoken words would be pure gibberish.

You seem to be referring to speeds at which the phonemes become indistinguishable. But that doesn't happen at double speed, which is what I was talking about. Nor is that the pitfall we were talking about, because the pitfall was that certain content rich texts might be too hard to comprehend at double speed. Rich content isn't a fact about the phonemes.