It sounds like a stipulation of Meruelo selling is that they bring back the Coyotes with an expansion team once the Phoenix arena situation gets sorted out.
Complete speculation on my part:
-Salt Lake City went to the NHL adamant about getting an expansion team, where the NHL realized that Salt Lake City can support a team right now.
-The NHL went to Meruelo and basically said "we'll buy the Coyotes off of you to sell them to a team that will move them to Salt Lake City"
-Meruelo and the NHL are negotiating what the deal would look like for that so that it doesn't end up in court, with Meruelo getting things like a guaranteed expansion team (if he gets an arena), a reduced expansion fee and stuff along those lines.
The NHL seems like the one that is pushing this move, just so they don't have to keep the Coyotes playing in Mullett Arena and be stuck in limbo going forward. It sounds like the NHL is trying to convince Meruelo to sell the team to them, rather than Meruelo trying to back out of having a NHL team.