Two big reasons this isn't going to happen.
1 - a larger league makes for better finances. They can get national sponsors to pay more, get better discounts on insurance, pucks, jerseys, software, etc etc.
2- Two leagues means competition between leagues for free agents, refs, team staff, and teams. If say Las Vegas isn't happy with the Wolves after a couple years they could get a franchise in the new western league and put a team in some other city, leaving Chicago's owner with no affiliation and therefore no team. He can't even sell his team, so he has to take a huge financial loss, or try to poach some other team's affiliation (leaving that owner in the same situation). Worse yet, Las Vegas could put their new affiliate in the rink at Hoffman Estates, so even if the Wolves find a new affiliate they have a team in the same market to compete with at the same level of competition. Above all else the owners want to protect their investment in the team, and if a situation like this happens they could be left with a suddenly worthless franchise. As it is now, with only one AAA league and only enough teams to match up to the NHL, the owners are always assured they will either have a team, or someone to sell their team to. The league isn't going to expand beyond the number of affiliations. With two leagues there is no longer that guarantee.