Maybe I'm missing something here ... 6 teams leaves an odd number of teams after the first round = 3 teams left, does one team sit while the other 2 lower seeds play? They will need to do something to eliminate the odd number. To get 2 finalists without a bye or around robin type format they need a qualifying field of 2, 4, 8, or 16 teams, anything else leaves an odd number. Am I missing something?
Regardless, they can, but they shouldn't, just jump right into the playoffs without 2 or 3 weeks of 'training camp' plus 2 or 3 warm up / exhibition games otherwise it's going to be really ugly skill-wise and dangerous for players injury-wise. One can argue it will be the same for every team, but if I was the players I would argue for proper prep time.
This format gives teams 1 and 2 a bye, while 3-6 play in a prelim round. Like the NFL. The only twist is that during the "bye" time, 1 and 2 actually play 3 games against each other to determine a possible switch of their seed number.
On the one hand, for the Atlantic, that twist is a little bit of bull - we're clearly ahead of Tampa in the standings. Not that they couldn't overtake us, but it would be surprising. But I get why they have to do it. The Metro, Central, and Pacific have 1, 2, and 3 point gaps for their division leader, with the 2 point gap in the west having a game in hand that could result in a tie if the game in hand were played. It's not fair to those second place teams that they don't have a shot at first place.
Those 3 games would almost be like a bonus "training camp" - yes, you're playing for seeding, but you can't be eliminated, and you might even meat the same team in the next round if both teams win. I would imagine play would not be AS hard as the games in the 3-6 and 4-5 series. It's honestly not the worst plan out there. But any plan involving playing this summer, or even early fall, is asking a LOT of the players, particularly those with families. Par Lindholm just had a kid, IIRC - imagine being told that you have to leave your 2 month-old for what could be six weeks, and THEN you have to tack on an additional two weeks to the end (and probably the beginning). Not every player may be interested, or even in the headspace to want to play. Plus, with players in Europe, coming back is even more difficult.
They need to figure out what the hell they're doing with the regular season, for the sake of arena employees and ticket holders. The Bruins' fund is still in "escrow" (or whatever you want to call it) because the season hasn't been formally cancelled, and ticket refunds are not available for the same reason.