I still believe the Knights are a unique situation. The fans strongly identified with the team from the beginning of the franchise. The winning helped but it wasn’t the whole story.
Such was not the case with Denver. They were going to see a winner. That team had a bunch of superstars headlined by all-world goalie Patrick Roy.
I think Seattle will be more like Columbus. Those cities don’t need something to rally around but they do need a winner. Abuse any fanbase with a bad team for long enough and people won’t show up. I don’t think any franchise would survive now with the horrible attendance Pittsburgh had in the early years.
I've lived on both sides of the border, and I've observed something interesting about NHL fans. There are only 8-10 NHL teams with a very strong fan base ... and by "very strong" I mean you could fill an arena with 15,000+ fans in the last weeks of a season even if the team is not a playoff contender. These teams include the Original Six (Montreal, Toronto, New York Rangers, Boston, Detroit and Chicago), plus Edmonton and Philadelphia -- and maybe Buffalo and Calgary now as well.
This is really apparent when you get north of the border and visit a place like Vancouver, and find that almost everyone you meet is either a Toronto or Montreal fan. The rest of the NHL's teams have fair-weather fans who will support their local team passionately, but only if the team is winning.
One of the problems the NHL has had in the last 25 years is that they've expanded the league to get national coverage for TV contracts, but in doing so they've put teams in places that have absolutely no historical or cultural ties to hockey. These are the markets where the teams tend to struggle when they have to rebuild after they've had winning seasons.
The article linked below from just two years ago lists EIGHT potential candidates for relocation among NHL teams. The list includes the following:
Colorado Avalanche
Nashville Predators
Columbus Blue Jackets
New Jersey Devils
New York Islanders
Florida Panthers
Arizona Coyotes
Carolina Hurricanes
The two anomalies in this list are the Islanders and the Devils. They are unique in that they are the second and third NHL teams in one metro area. The Islanders would probably come off this list right now, since they are a hot team and they will be moving to a new arena on Long Island in the next couple of years after playing in an arena in Brooklyn, NY that was totally unsuitable for hockey.
The rest of those teams all have something in common: they were expansion teams or relocated from other cities since the mid-1990s. In other words, the cities where they play were probably never strong hockey markets in the first place.
Historic Storm Produced History for Devils in '87
The New Jersey Devils were an embarrassment to the NHL for the first several years after the Colorado Rockies moved there in the early 1980s. Wayne Gretzky even had one of his very rare intemperate moments as a professional hockey player at that time, when he referred to them as a "Mickey Mouse organization" after the Oilers scored 13 goals against them in one game.
But they slowly improved through the later years of the decade, and finally made the playoffs for the first time in 1988. The article above was published around the anniversary date of one of the most bizarre games in team history in early 1987, when a blizzard dropped two feet of snow on the New York City area and some of the players took hours to get to the arena at the Meadowlands Sports Complex. The visiting Calgary Flames were staying at a hotel not far away, so they made it there on time. But the Devils didn't have enough players to field a team at game time, so they delayed the start until after 9:00PM.
There were 11,000+ tickets sold for the game, but only 334 fans showed up. They soon became legends in Devils history. The team gave them all kinds of free merchandise at the game, and even 30+ years later they have periodic reunions and are still remembered as the "334 Club."
You may even see one or two of them at Devils games today. They're the ones who wear what looks to be a regular Devils jersey from the front, but on the back it has the number "334" instead of a player's number. LOL!