Interestingly, there is both an extremely statistically significant correlation of birth months vs. NHL success and a meaningful boost in production the older you are for your draft year.
Yes, again my understanding is that, the “granted extra ice time and opportunity compounded across their youth hockey experience simply by virtue of being slightly more physically capable relative to their cohort…” is suspected to be driving the pattern you’re noting.
(Probably slightly more cognitively capabilities for these players is probably also a factor)