I think the best course of action for this decade of the NHL would be to:
2024 - Relocate Arizona to QC and they temporarily play in the west
2026 - Expand to Atlanta
2028 - Expand to a western conference city
2030 - Expand to a western conference city
2030 - Expand to Arizona 2.0
Those western conference cities could be any two of Houston, San Diego, Portland, or Salt Lake City. It's a bumpy road but eventually everyone wins.
36 teams
18/18 conference divide
QC gets a franchise
AZ gets their much needed reset
Everything is based on arena and owner.
Houston, comes down to Tilman Fertitia and whether he will pay the expansion fee which is now much greater than when he balked at the price a couple of years ago. If he's still not interested in the price the NHL wants, there are only 2 real options for the NHL to get into that market. Either Fertitia sells the Rockets and thus you have someone else to work with or another party builds a new arena in the "burbs" of Houston.
Portland - currently still part of the estate of the late Paul Allen. Going to be sold, just a matter of time. $4 billion for team and arena, possibly more. Then if you add in the NHL team, pushing $6 bill if the NHL wants closer to $2 bill for a team. Arena is ready to go, but like Houston, depends on the new owner of the team/building. I don't see Portland as a large enough market that someone would build another arena to compete with the Moda Center.
SD - working on a new arena. Current target capacity 16K, but say it's expandable to 18K. Main thing for the NHL is to keep an eye on it and be in touch with the developer, and Kroenke, the Avs owner is part of the development group, so easy for the NHL to talk to him. This new arena has to be built and configured to support an NHL team, not designed like Nets, Warriors, Jazz, Suns arena that is basketball specific and only holds 14K of fans for hockey.
Utah - need a new arena as it's not NHL compatible. Building built in 1991. PHX would have torn theirs down and rebuilt a new one vs try to retrofit it for the NHL. Probably has to be the same for Utah. Or built on another site.
ATL - working on a new arena in the burbs. Probably requires the NHL awarding them a team before they get the greenlight to proceed with the development from the city/county.
QC - arena ready to go. Who is going to own the team and do they have the money to do so. Then its really the NHL's appetite to return to QC.