It probably depends on the kind of innovation you're talking about. IIRC, most of the advances in mathematics come from younger mathematicians. Just like you're less likely to find innovative chess play in older players. So I'd imagine that most innovation that relies on pure ingenuity would come from younger folks.

On the other hand, innovation that has a more social component to it or relies more on life experiences would probably favor those who've had more opportunities to hit on the right experience to trigger their innovation.

The term "innovation" is probably too broad/generic to make any meaningful conclusions. It needs to be subcategorized to be useful in the way the article is positing. And from the sound of it, the research is using patent applications as a proxy for innovation which seems somewhat biased towards older people who understand the importance of getting all the legal ducks in a row, not to mention how many patents are anything but innovative. It also seems overly narrow since it misses lots of innovation that doesn't get codified as an invention.