Not sure about the beta but the full version release should be able to have that many teams. The customization should allow you to move teams and expand them in your league.
The NHL hasn't been talking expansion, they have been talking relocation. If anything retraction should be happening to 22 teams but that shouldn't stop you from expanding your NHL to more teams.
I wouldn't think relegation would be possible to setup in the NHL, it might work if you want to do it manually but not perfectly. Would players get released from their contracts when a team is relagated manually, i doubt it. It would probably case issues.