I don't know the details of what you are saying, but I assume that a large part of the revenue for NHL Olympic participation goes directly to the NHLPA bank account. And then there is the matter of the ninety plus percent of NHL players who get the luxury of a 3-week Caribbean beach vacation right in the middle of the season while the small few are off fighting for Olympic medals. Yes, the NHL has to negotiate with the NHLPA, but if the players don't get their way, what are they going to do? Transfer to the KHL? Play the next couple of seasons for Kunlun in Manchuria?
Canadians sense an easy path to a Gold Medal, with no real opposition in their path. But the NHL already has maximum support from Canada locked up. I see no interest anywhere else on the globe that would really press them to do everything that it takes to shut down the league for 3 weeks mid-season.