There is plenty of statistical evidence that it is easier to score given equivalent talent and age in the CHL than in the NCAA. You can quibble with the accuracy and precision of the conversion factors, but saying that there is no basis for comparing leagues goes a bit far.
Larkin scored at a 1.34 ppg clip last year at UMich. Given how he's playing at the NHL level this season, do you have any doubt that he would have scored at a higher rate in the CHL? What about Eichel? He scored at a lower rate than Strome in his draft year in the NCAA. I think it's pretty evident that he was a much more potent offensive player in his draft year than Strome. Hanifin was just over 0.6 ppg in the NCAA, and is a solid NHLer this season.
Sure, there are vagaries in the individual circumstances, but the notion that leagues don't differ and that the NCAA is not harder than the CHL to score in at the same age just doesn't have evidence to support it.
I think Connor hit the sweet spot this season in terms of league, linemates, etc. and his point production is likely inflated on that basis. I could see his production going down a bit next season if he stays in the NCAA. But that happens with top end CHLers, too.
Connor's offensive prowess shouldn't be a surprise, though. He was a very high end offensive producer in the USHL, which was a good sign. For what it's worth, one NHL scout commenting on Connor in his draft year (quoted by Hockeyprospect.com):