Here's been my experience so far, coupled with what I learned from parents with kids older than mine.
Generally, the kids that get most attention from the program are the better kids. So if your kid is on a B team, he's not getting anywhere near the skills attention that the higher ranked kids are.
The difference between the A tiers and B at u-10 normally boils down to who are the biggest kids and who got on skates earliest. Then it will become who can afford the privates.
As the kids get older, yes, the kids who have the most skill earlier will likely have the more skill later but then life gets in the way. Who wants to play other sports, who wants to chase tail, who's drinking, etc. The introduction of checking also adds an additional dynamic.
I kind of laugh at some of our parents who stress over "tryouts" and all these parents who switch programs every season because they think other ones are better. They're generally all the same for one reason or another. You try to move to a "better program" and there's more politics involved. It's a trade off.
All these kids are headed to beer league. USA hockey really doesn't promote or care about what's happening in New Jersey. They know where their bread is buttered, the Midwest and New England.
@Dunny has seen way more of it than I have.