Just out of curiosity, i was thinking of some recent examples of goalies emerging as Elite/very good who were rated that way as a prospects before the draft.
Vasilevskiy, Gibson, Oettinger, Demko, Fleury, Lehner, Rask, Hart were are 2nd round or higher, maybe a few others, but it's a short list. Oettinger and Demko and Hart are too early in their career to make any statements about.
In contrast, you have the last 10 Vezina Winners being:
Hellebuyck (130th), Vasi, Rinne (258th), Bobrovsky (undrafted), Holtby (93rd), Price (5th), Rask (21st), Bobrovsky, Lundqvist (205th), Thomas (217th).
For cup winners over the past 10, Quick was a 3rd rounder, Crow was a 2nd, and Murray was a 3rd. The others are mentioned above, save Binnington, who clearly seems like a lightning in a bottle goalie.
Seems like most goalies are dumb luck.