This ignores the point (that Perell makes in the essay) that learning via lecture is a horrible way to learn much of anything to begin with.
Now I could see a counter point where you speed up a lecture, find the new information that interests you, and then use that as a jumping off point for repetition. For example, dive deeper into other sources, take notes, use flash cards, try applying what you've learned, and so on.
But just consuming 10 mins of new info from a full lecture at 2.5x speed and then moving on probably isn't doing much long-term learning.
Off-tangent: modern lectures are still a better way to learn something than original lectiones were ― the lecturer would read the book by some prominent author, and students would listen to it and take notes... and that's it. That's what lectio literally means: "[an act of] reading". And before the invention and spread of the printing press, it absolutely made sense ― books were rare and expensive.
Today, of course, lectures during which the lecturer simply reads the textbook and does nothing more, are rightfully considered to be the worst: a student too can read the textbook himself just fine!
Now I could see a counter point where you speed up a lecture, find the new information that interests you, and then use that as a jumping off point for repetition. For example, dive deeper into other sources, take notes, use flash cards, try applying what you've learned, and so on.
But just consuming 10 mins of new info from a full lecture at 2.5x speed and then moving on probably isn't doing much long-term learning.