the ncaa is a way better developmental environment than the ahl for most prospects, especially under 20. most schools have excellent training facilities and the social and academic environment is a big plus. i think it would be pretty rare you'd want a player to leave the ncaa to come to the ahl unless there was an academic problem. also, you don't want to burn elc years if you can avoid it.
Facilities, travel, and support staff (strength/conditioning coaches, nutritionists, etc) likely better at most major NCAA hockey programs like Michigan, BC, BU, Minnesota, UND, Notre Dame, etc. than you get in these small market AHL cities.
Most 19 year olds, unless they have truly dominated college should go back to college. Connor put up 71 points as a FR at Michigan. So, he went to the A at 19. That's a scenario that makes sense.
ELC year likely to be burned by Wallinder this year anyways when he signs after the BU season.