I'm extremely bullish on the future of Calgary/Alberta, and I've really formed this thesis in the last few months. I suspect that there are a couple strong trends working in Calgary's favour:
1. For many folks (myself included - as well as many of my peers in the technology industry) job location has become permanently disassociated with living location. The biggest problem working against Calgary for many people was that there weren't any relevant jobs here. You had to go to 'superstar' cities if you wanted to work in your chosen field. That isn't necessarily true anymore. This should reduce the barriers to folks moving to Calgary.
2. The relative cost of living is much lower than other cities, making it an extremely attractive value proposition. I've personally seen many people move from Vancouver/Toronto to Calgary, partially because their role was made remote and because they can afford a home here. I suspect that this trend will continue to play out for a long time.
3. I think the investments made to diversify Calgary's economy are starting to fruit, and you're seeing lots of home-grown tech companies, but also a growing film industry, growing ag-tech, and alternative energy growing in Calgary. They obviously have a long way to go to replace O&G, but I think it may happen faster than people suspect.
4. The quality of life here is fucking superb! Ignoring all economic constraints, it's a great place to live. Close to the mountains, 4 nice seasons, its clean as hell, limited crime, I think people take a lot of this stuff for granted. Of course, you combine this with the removal of barriers to entry (e.g. job locations) and the cost of living and it's a no brainer for many people. I think there are a lot of positive virtuous cycles in the near future.