Likely doesn't? You might want to re-crunch those numbers. Calgary was easily a bottom 3 team in the league this year if it wasn't for Markstrom's outstanding play. The only upgrade to their roster for next season is likely Poirier instead of Okhotiuk on the 3rd pair.
Meanwhile all the other teams around them in the standings (Seattle, Ottawa, Buffalo, New Jersey, Utah, and Montreal) are actively trying to improve their rosters for next season. Then you have the teams filled with loads of young prospects with high potential like Anaheim and Columbus. At some point those prospects start tapping into that potential and the teams take massive steps forward.
I would say Calgary is all but guaranteed to finish bottom 10 next year and most likely bottom 5.