I spent a lot of time writing TI-BASIC and PHP/MySQL when I was about 11-13. Stopped programming in any serious capacity for about a decade.
When I picked up coding again as an adult, I found that although I had forgotten language-specific details (function names and arity, syntax, semantics, and so on), the flow and rhythm of programming had never really left me.
Since then, I've occasionally offered advice or informal tutelage to friends who are picking up programming and have asked for help. My observation is that programming seems to "click" with those who have, at one point or another, built a trivial project or script without following along a tutorial too closely. It doesn't matter how long it's been since they last wrote a line of code, the actual practice of coding sticks with them, and it greatly eases the challenge of further learning. Rote activities like codecademy don't seem to act the same way, since the user never gets into a flow state.
The article linked in the OP doesn't mention natural language learning, but I wonder where that sits in the proposed declarative/procedural binary. There's no getting around the brute memorization involved, but it does seem like certain language acquisition skills can be applied abstractly to grammar comprehension, semantic pattern recognition and the like, and can consequently make one's third or fourth language easier to learn than one's second.