I hadn't got that far, but went to have a look and yeah, as a fellow pianist I concur. Then I saw the following paragraph:
"Another strategy that works well in both humor and famous EDM drops is "violating the expectation", but you need to know the expectation before you can violate it. Once you learn music theory, you're able to violate it in ways that resonate."
You absolutely do not need to know anything about music theory to know how to play with expectation of a drop. If you aren't just feeling what the right thing is to do then you're not being creative, you're just following a set of predefined rules, which is likely to be dull.
For me creativity comes about when the brain stops 'actively thinking' - when I enter a flow state and creative things 'just happen' because of that zen like state. I get that when I DJ, play the guitar, play the piano, or even when I write code. It's like the subconscious brain has taken over for a while and is working on instinct.
It's true that you don't get to that state if you haven't practised enough. That's primarily because you don't want to be actively thinking about hitting the right key, finding the right fret, or knowing how something is architected. That active thinking will kill the creative flow, stone dead.
I'd argue creativity isn't memory in that sense, you need (memorised) technique, but it seems far too reductive to say that the creativity that emerges from ones subconscious is only memory -- it's clearly 'something else'.
I've also met plenty of smart people in my life who are creatively bereft!