I recall hearing that with the new BMO centre, Calgary is attracting much larger events and is, as a result, in need of about 5 decent size new hotels in the downtown area. Truman's project, which is rumoured to be massive, probably eats up much of that demand on its own if the rumours of its size are true.
Anecdotally, a friend of mine is coming to Calgary in June for a wedding and has had a terrible time finding a hotel. The only rooms available were by the airport, and she eventually found an AirBnB, Part of the reason for the scarcity of rooms is the Global Petroleum Show is happening then, but all the various festivals and expos, one of the biggest Comic Expos in North America now, and of course Stampede all bring in a lot of visitors.