Ottawa I can see, mostly, but Calgary? This isn’t 2005, and nowadays a lot of retailers start in Calgary or eschew Edmonton altogether. Both Ottawa and Calgary also have stronger urban retail than Edmonton. Pretty much anything at South Common can be found in other cities, just in separate shopping centres. The key retailers in WEM are usually found at Chinook too. Obviously it isn‘t an either/or, as some retailers do come to Edmonton first, and some ignore Calgary, even, but the gap is pretty much non-existent now, as for every retailer that goes to Edmonton first, there’s another that goes 300km south first.
I agree that City Centre will continue to struggle as many of the destination retailers will skip it in favour of the much nicer, larger, and more profitable Kingsway slightly north. For the first-in-town or only-in-town options, WEM, Southgate, and South Common fill that void nicely. The only way I can see City Centre thriving as a mall is if the downtown population, of either residents or workers or visitors (but ideally all of the above) explodes. When you have that high of a density, having multiple locations of certain things close by becomes more viable.
Retail does have a place downtown, and will be a key piece of making the neighbourhood more vibrant and desirable and functional, but I think we need to cover the basics first before we chase Uniqlo or Lululemon. Unfortunately all of those basics are found in suburban-style shopping centres on 104th Ave, rather than on Jasper Ave, 102nd Ave, 101 St, RHW, 104th St, 124th St, etc. I like the Rec Room idea, though. And keep the Landmark Cinema, somehow. And the food court, I suppose. But the rest can be turned outward, and imagine the complex being headed by Rec Room and some of the Unity/Brewery staples like Safeway, Best Buy, and London Drugs. Then leave some room for smaller tenants with an emphasis on unique attractions rather than traditional mall retailers.