It also poses wildly different challenges, where the metrics by which one is to judge the "degree of having attained knowledge" in the broader sense of the word, depends entirely on which of those aspects one value.
Some literature refers to this dichotomy as "instrumental" or "relational" understanding. You see this very clearly in math, where students can recall the facts of equations, but they don't understand it.
It can very well be that the author of this article is aware and appreciates this distinction. But, the phrase and title of "learning is remembering" will certainly evoke suspicion. Just because it is much easier to remember something one understand, does not mean that by remembering, one understands.
For some reason we then give them degrees and call them educated if they remember all those things they don't understand in an exam.