I remember when 3 on 3 All-Star games were gimmicky....good times.
Thing is if the hockey turns out to be fantastic, nobody cares.
That all depends, however, on whether or not players are motivated to play hard. I think they will, because as much as players play for their nation, they also care tremendously about their own sense of pride. If you can't motivate yourself to play against the best players in the world, and for once it actually IS the best players in the world, then that's really an indictment of your own competitive fire.
The NHL was hesitant on going to the Olympics even when the IOC paid for insurance costs. Now that it's off the table entirely, then it's understandable that the NHL would say no. Maybe this changes with a new head in 2022, but the NHL more than any other major North American league stands to lose the most. The MLB didn't send players to the Olympics while baseball was an Olympic sport because the Summer Games coincide with the season, and quite frankly the IOC had no need to bring in baseball players because the Summer Olympics are the biggest celebration in the world and have enough marquee events and stars that paying insurance costs would bring very little benefit to them (and make no mistake, the IOC is just as much about the business as any major league). On the other hand, the Winter Olympics have far less events and marquee names, thus for a number of years it made good business sense for the IOC to bring NHLers along, because hockey was and still is arguably the biggest marquee event for the Winter games.
The NHL took a gamble when they chose to send players over and while Olympic hockey had its moments, from a pure business perspective it didn't bring the kind of return that the NHL needed to justify the risk of having a star player injured outside of league play (like John Tavares).
The World Cup makes the most sense for the NHL. This notion of nationalistic pride is great, and if the NHL has its way the World Cup will return to the regular "international" teams after this one, which theoretically solves a lot of the problems fans have with the tournament. I don't necessarily like everything about it (thanks crappy commercials) but I am okay with best on best and this is as close to it as we'll get in hockey.