I know 99% of the hockey world don't care about the Ducks and, furthermore, tend to significantly undervalue everyone and everything that comes out of Anaheim, despite the Ducks having produced a huge chunk of quality players they didn't even keep in the past 10+ years (most notably William Karlsson, Shea Theodore, Brandon Montour, Hampus Lindholm).
With that being said, Dostal most surely is among the NHL's best goaltenders as of right now. Is his stellar play sustainable for a whole season? Most assuredly not. Does he look like a bonafide 1A elite goaltender in the making, who has played at a very high level already for more than a year? Well, everyone who follows/followed the Ducks will tell you that this is case.
If Dostal played for a coach who actually knew what to do and behind a competent defense, would he be considered a Vezina candidate. Imagine him on a team like the Rangers or Florida. Hard to argue against him being deserving of some silverware so far. But of course, there's a lot of ifs and not enough sample size to fully project his foreseeable future.