I agree, I am super suspect of this article being true. Most of it is about training time. And Teens have much much more of it, given summer vacation, or, just not having any responsibilities ever.
I would say any decline I've noticed is due to "training time," yeah. I will sometimes go a few months without playing... jumping back in will take me a few rounds to get back to "good," and I feel a similar slope when I start new games. I imagine if I played from end of work til sleep every night like when I had time as a kid, I would probably be as then-me, if not better.
