The league is all about making money. In this case, it's probably really cheap to run these playoffs, since players I don't believe actually get paid in the playoffs anyways, so for sure the league will make money by running anything resembling hockey out, even if they have to finish the season on outdoor roller-blade rinks in Florida.
MLB, on the other hand, has a real problem, in that players have to get paid during the season. For their perspective, if they play half the season, they should make half their income. But MLB obviously will want them to play for much less than that.
I'm a little surprised that the NHLPA has actually been willing to go ahead with these proposals. My gut says that behind closed doors, there's basically a "agree to this right now and we'll make sure that we have a proper cap discussion for next year", knowing that if the NHLPA decided against getting these games in, the NHL would be able to really hammer them down when talking about next year's cap/escrow.