I've always thought that players with low hockey IQ tend to bust as it's not fixable. How accurate is this type of thinking?
It's a bum answer, but..... Depends.
Take it from the other side... A guy like Corey Locke had extremely high "IQ", but not the physical tools & mindset to translate it to a NHL career...
Chipchura imo had a pretty high hockey IQ, but the injury impact on his game or just inability to transition it to pro level, took away his top 9 potential...
"IQ", physical tools, mindset & confidence... I don't know that anyone has, or can, map out an exact formula, but for each elevation to a higher competitive level, some combination of these factors needs to come together for an athlete to make it, let alone thrive.
JP obviously has a good amount of physical tools.
His success at various other levels, suggests he has at least the capacity for an effective mindset. Confidence doesn't seem to be the issue (though ego/arrogance can easily be a sign of a lack of confidence).
That he was an unstoppable force in WJC's one year & then held scoreless a year later at the Senior WC's, points perhaps to a reliance on physical edge for success, which is not a great sign....
Player progression is far to complex to simplify to 1-2 variables in terms of why/how it works out...
Dan Cleary is another great example. He was McDavid-esque in his pre-draft hype... Completely failed to live up to that height (admittedly lacked professionalism & relied too heavily on "natural talent" for too long and it ruined his chance at stardom)... But, caught himself, changed his mindset & ego, and reinvented himself as a great middle-6 player (likely due to his great hockey IQ) and ended up having a good career even if well short of the potential he had... A transition guys like Daigle & Stefan weren't able to pull off.
Imo, JP either figures out how to be an impact top 6 NHL offensive contributor, or plays out his career in Europe... At this point, he's young enough and has the right physical tools that, if he can find the right mindset or be supported into growing it, the ceiling is still attainable