The ACHA has filled that void. What started out as 'club hockey' has become real college hockey. Yes, something like 92% of all NCAA freshmen hockey players are 21, because they either played 2 years of junior or repeated multiple times at schools like Nobles and Shattuck.
So the kids who want to go direct from high school to college, who can't afford to pay for junior and aren't quite good enough to play in a free junior league like the NAHL or USHL, can still get recruited and/or tryout for their school's ACHA team. There are only around 150 NCAA hockey teams, but there are over 400 ACHA teams in the country now. Some schools, like UMass Amherst have two ACHA teams, in an upper and lower division. They get over 100 kids to their trouts, and most of them were stars and captains in high school. The best ACHA teams can compete with D3 NCAA teams.
The ACHA teams west and south draw big crowds too. Not so much here in New England where most schools with ACHA teams are overshadowed by their NCAA teams but it's still a great experience. You play in NCAA rinks, you play by NCAA rules, there are playoffs and a national championship.