Well let's look at a sampling of the best NHL starters from last year then shall we?
Player|NHL Start Age|NHL Primarily Start Age|Minor League Seasons
Carey Price|20|20|0
Devan Dubnyk|23|24|4
Steve Mason|20|20|0
Corey Schneider|22|23|3
Corey Crawford|20|25|5
Pekka Rinne|22|25|3
Braden Holtby|21|23|3
Tukka Rask|20|22|2
Henrik Lundqvist|23|23|0
Roberto Luongo|20|21|1
Semyon Varlamov|20|21|1
Eddie Lack|25|25|3
Marc-Andre Fleury|18|21|1
Ondrej Pavelec|20|22|2
Jon Quick|21|22|1
Sergei Bobrovsky|22|22|0
Jonas Hiller|25|25|0
Ben Bishop|22|26|4
Jaroslav Halak|21|23|3
Frederik Andersen|23|23|1
That's not even including the impact young goalies like Petr Mrazek (hey another 5th round pick just one year older than Hellebuyck already making a huge impact, playoff starter!), Andrei Vasilevsky, or John Gibson who are future stars at 22 or under already strutting their stuff. Or counting guys who made an impact young who fell just outside this range this year for a variety of reasons despite great talent like Jonathan Bernier, Calvin Pickard, Phillip Grubauer, Joni Ortio, Martin Jones, Darcy Kuemper, Kari Lehtonen, James Reimer, Robin Lehner.
I hardly think I am out of line to think 22 is not at ALL too young for a goaltender to make an impact. They certainly can. I know I would be MUCH more comfortable with a Hutchinson/Hellebuyck tandem than an Pavelec/GOD tandem. And yes Wiebe there is a VERY immediate need to get Hellebuyck to the NHL. The need's name is Ondrej Pavelec.