They indeed had a big advantage in both 2010 and especially 2014. But that was with players drafted before 2009, after that its not That special (except McDavid ofc). A lot of their forwards that was so dominant those years are in a downswing and its not as great ones coming up (although still great). Crosby is 30, Toews had a really poor year this year, Bergeron is 30+ as well, Giroux is getting even slower, stamkos is hurt, Tavares had a bad year for his standards.
Imo they are still the best team, but it should be closer 2018 than in previous years.
Russias offense is also a lot worse than in 2010 since their golden forwards generation of Malkin, Ovechkin, Kovalchuk, Radulov (and Datsyuk&Semin) are on their downswing as well. The next generation of Kuznetsov, Tarasenko and Kucherov are not as good as the others were back then.
Sweden will be competitive since they get all their young stud Ds, depth and Bäckström.
Finland will be better with an older Barkov and Laine, but also some good Ds they missed the last time. Last time Määttä were by far their best defender, now hes their 3rd-4th best. Worse depth in the crease, but Rask is still a top goalie, and Rinne a capable one as well.
Czech Republic will finally field an NHL d-crop and has a couple of young good players up front with Voracek&Krejci as veteran guys.
Switzerland will be able to field a team full of NHL players for the first time.
Slovakia is dead, and has been since 2010.