There's typically only two reasons why Edmonton gets consideration for this kinds of events:
1. Commonwealth is the only grass stadium in Canada capable of seating over 50thousand people. Pretty sad, but true.
2. Edmonton tends to draw well from the Calgary region as well, and since the Calgary-Edmonton region tends to be the wealthiest in the country, there's a higher chance of selling out.
Frankly, I'm pretty bummed Edmonton likely isn't getting a friendly, I was pretty stoked about going. Even though I'm moving to Southern Ontario for school, I doubt it'll be in time to make a trip to TO.