Ryan Van Horne
aka Scribe
This is the type of insight I come here for. Some others on this site should take pointers from you.Prep is certainly the top team, but the 16U team is always loaded with kids who could just as well be on the prep team. Clayton Keller made the jump that MacKinnon didn't a few years after, but that was a weaker prep team than it was when he was there. Even two years* after MacKinnon, a fellow maritimer named Nathan (noel) made the jump MacKinnon didn't, and he is nowhere near what Mackinnon was. Also worth noting Mack is a late birthday.
These days SSM gets players recruited like crazy from junior teams so the prep team is thinner than it was in the 'glory days' as far as I can tell. For example Jackson LaCombe who went early on in the draft this year had to switch to defense on the prep team two years ago because they didn't have enough blue liners. Not something that would have happened in the past I would wager.
For what it's worth 18U hockey (what prep plays) really isn't usually 'better' than 16U in america. It's just older. In many ways 16U is more skilled and certainly was more 'relevant' for scouts, at least until 15U became popular. I'm sure it is still that way to some extent. But for a young talent a year of showing what you can do against decent 17-18 year olds can be valuable.