With the pending Mirage closure next week, Las Vegas will has lost a lot of hotel rooms in a short amount of time. According to a Nevada-based gaming analyst company, two of the largest casino operators on the Las Vegas Strip are poised for substantial economic gains following these closures. That equity research company, CBRE Group, believes their data shows that the shutdown of the Tropicana Las Vegas in April, as well as the Mirage closures on July 17th, will create a favorable market for Caesars and MGM. Losing both of these popular resorts means the removal of nearly 1,500…