Anecdotally I stumbled upon this phenomenon when trying to learn how to play the piano. I noticed that at the end of a session I make so many mistakes and feel like I didn't learn that much, but coming back to it after a day or two I really felt the difference.
Motor learning is quite different from the type of information the article talks about. I tried adding dance moves into Anki to do spaced repetition and it's extremely obvious that it's a great way to remember a move very badly but never getting good at it. Compare that to the geography deck where Anki is just perfectly suited for the task and smashes it.
Learning to play an instrument feels like magic.
You fail the whole day.
Don't have the feeling anything sticks.
Then, the next day it works right from the start.
No new insights, nothing, it just works.