There's a league-wide pronunciation guide Doc Emrick edits/curates that is used pretty universally. A lot of broadcasters refer to it. /(
https://nhl.bamcontent.com/images/assets/binary/300636256/binary-file/file.pdf). There's also a college hockey version. I work in the ECHL (former PA & now PXP) and I've consulted both many times if I am unable to get to a player to ask him personally. Nowdays, several players' pages on EliteProspects have an audio file of them saying their own names. When I did PA for the ECHL All-Star Game last year, I had to learn a *bunch* of new players' names and used all those tools to prep, then found whatever players I could to ask them pregame and confirm.
Jack has said during broadcasts he goes up to players and asks them for the pronunciation of their names (most notably with Alex Chiasson, whose name he was pronouncing "chee-uh-sawn" for a while when everyone else pronounced it "CHASE-on" (as it is in the pronunciation guide). Jack said he asked the player personally and was told that was how it was pronounced.