Detroit was never going to be a short-term turnaround, progress has been made though. One more win and they'd have been a playoff team and suddenly the narrative looks very different.
I think how they follow up this season will be critical, can they actually claw their way back in? They're lumped in with Pittsburgh, Philly, Buffalo, Long Island, Washington, New Jersey, and Ottawa. There's even a chance that Tampa slips down, they were very, very dependent on Kucherov this season and I'd be surprised if he hit 140ish points again.
It's a tough league, lot of teams out east are trying to either remain competitive (Pittsburgh, Washington, Long Island, Philly, Tampa) or take that next step (Buffalo, Ottawa, Detroit, New Jersey).
Only eastern teams I'd say are probably locks next season are the Rangers, Hurricanes, Panthers, and Bruins. Toronto's tougher to gauge, we could see significant change in Toronto, I reckon they're probably a playoff team though.