I think if a player is drafted in the first round but isn't ready for the NHL they should be able to play in the NHL. They're not going to learn anything new in Junior and they get a chance to learn the teams system at a younger age.
Its not like all first round picks who go back to junior dominate the league.
The way it gets talked about on this board, you would think every drafted player who goes back to junior and makes the underagers look like peewees.
Its not the case.
Toffoli scored 57, and his team fizzled out in the first round....I would say he has plenty to learn.
Even Kassian was said to be a man amongst boys, yet still couldnt pop 30 goals in the OHL.
Develop your skills, learn lessons...its not like junior is purgatory. A lot of times the junior players would play limited minutes in the AHL too, playing in all situations against your peers can never hurt.
Look to D'Amigo last year...left NCAA for the AHL and finished up in the CHL because he wasnt ready (I know he wasnt a first, but a skilled player nonetheless).