The kid is making an absolute fortune playing in the AHL isn't he? Something like 925k USD? Which is like 1.25M or so Canadian.
He is playing about three miles away from the ACC, everyone knows who he is, he is a rockstar in Toronto already, and he is getting used to dominating...
Being as good as he is, it allows him to train and work on things that he might not be able to do in the NHL.
If the Leafs somehow get into playoff contention, sure, MLSE might not be able to help themselves and call him up, but till then, the kid is living a lavish lifestyle in the A.
Its a good situation and I bet the kid, at that salary, ain't minding too much.