I don't see any way that a multi-tier system works for the NHL. It is a niche sport that doesn't have the number of fans nor earn enough to support something like that. Logistically it would never work.
Has any North American sports league even tried a promotion/regulation system? I think to even attempt such a thing with hockey would require an absolute overhaul of the entire pro hockey system (NHL, AHL, ECHL, etc.), not to mention how many teams would be in any such league to begin with how many pro tiers, etc. On top of that, does that mean the NHL Entry Draft goes the way of the Dodo, which in turn means we go back to something like the old sponsorship system? Just seems like too much work for something that might not even work here.
Now, I don't necessarily see anything wrong with the current regular season/playoff system in the NH (well, the point system, but that another matter entirely), but...
I had thought up of a way that the NHL could potentially change things up while maintaining a 32 team, 82 game schedule (technically) and doing away with the draft lottery entirely.
The season would be split up into two parts. Each team would face off against each other twice, taking us up to 62 games. The point system would be three points for a regulation win, two for an overtime win, and one for a shootout win. No points for any type of loss.
After each team plays 62 games, they are split into two divisions.
The top 21 teams compete in what I call the "Qualification Round", trying to get one of however many playoff spots there are. The standings get reset to 0, and each team faces off against one another once (20 games total). If the playoff system remains the same, then 16 teams out of 21 would qualify for the playoffs. If it's different...you do the math.
The bottom 11 teams would compete in what I call the "Draft-Ranking Round", trying to earn themselves the #1 overall pick. Again, the standings get reset to 0, and each team would face each other twice (20 games total). The top team in this round get the #1 overall pick, the second-place team #2, the third-place team #3, etc.
I wouldn't expect anything like this to ever get implimented by anyone ever, not to mention my idea's many pros and cons — some I have though of, some I haven't — but it's always fun to try to come up with new things.