It raises the question then of how the equipment staff assigns numbers. Never seen an article or interview on this.
Every team kind of does their own thing
The Sharks have a goofy system where they operate on one pool of numbers shared between the big club and the Barracuda in the AHL so there are never 2 players sharing a number in the NHL and AHL at the same time, but it means the Barracuda roster is constantly populated with a bunch of weird-ass numbers no one would ever pick on purpose
The other end of the spectrum was the Devils under Lamoriello where NO ONE was allowed to wear high numbers, except for when they were like Jagr and Mogilny, because no one is bigger than the team, except of course for the guys who are bigger than the team
I like it when teams just let the rookies pick for themselves, here's the list of available numbers that have not been issued or retired, take your pick, and that should be the end of it, a number is personal to so many players that the fact they are predetermined for so many rookies is just kind of dumb and bizarre old timey-thinking