First, they were already saying that last year with Vegas' success.
Second, literally each Division leading team lost to a WC team. Avs over CGY in 5 was a huge upset. Blues over Jets, Stars over friggen Nashville??
And yes, Isles and Canes. No one would of guessed they would even MAKE the playoffs in Oct. Regardless of stats, Caps and Pens had the stars and playoff experience. Those were huge upsets (especially the Isles sweep). It's not my opinion, it is literally everyone's opinion. THEY RE DID THE ENTIRE BRACKET CHALLENGE.
Vegas was a damn good team last year, though. Also even this year you still heard people saying that they lucked out a bit that last year's Winnipeg and Nashville teams had to play a 7 game war in Round 2 (certainly didn't hurt them, and another reason why some still want the playoff format changed again). They were also one of the hotter teams this year, and we all know how their Game 7 in Round 1 could have gone differently without THAT major penalty.
Yes, each division winner lost to a WC team...although it should be pointed out, I already agreed that Tampa was a huge upset. But Boston had a better record than ANY of the other division winners.
The 5 Metro teams that got in had point totals of 104, 103, 100, 99, and 98. 6 point spread between 5 teams is hardly large, plus we were going in against that Carolina team that had been playing amazingly well in the 2nd half of the season, down a top D man, losing Oshie, and with a rookie head coach (Trotz with Isles). For that to go double OT in Game 7 doesn't really qualify as a huge upset to me. I'd also disagree about Canes not being picked to make the playoffs in October. Canes have been the advanced stat community's baby for the last few years for how they control shot/scoring attempts in their games, but weren't getting quite the finishing talent/goaltending to make the next step.
Isles I'd agree nobody picked to go in October, but it's hardly shocking for a surprise team to get in, also with the unusual (unprecented?) variable of being coached by the coach who won the Stanley Cup the previous season. Pens were bad in the 2nd half of the season, and again Isles were the higher seed. Sweep was unexpected, but looking at the Penguins blue line and knowing Sidney Crosby managed 1 assist and 0 goals in 4 games...you might have guessed that would be the case.
I'd say Avs over Calgary was a moderate upset, although my first response to your original post was that goaltending needs to come through, and Grubauer put up a 0.947 sv % over the last 4 games of that series, which is pretty crazy (maybe we should have traded Holtby?). You also had the Avs winning both OT games in the series, which were huge momentum factors, especially when you consider they had to tie BOTH of those games with under 3 minutes to go in the 3rd (and one was a comeback from down 2-0 in the 3rd in Game 4). Also, not to beat the drum about playing well down the stretch...but Colorado went 7-1-2 in its last 10 to secure the final playoff spot, 16 points out of 20. That was 2nd best in the league in the last 10 games, 2nd only to...your Stanley Cup Champion St. Louis Blues.
Blues over Jets? I mean they both had 99 points in the regular season, both only 1 less than Nashville who won that division, and Blues as we've noted had been super hot while the Jets came into the playoffs pretty cold.
Even Stars and Nashville you're only talking about a 7 point difference between the two teams, and Dallas was literally the #1 defensive team in the league going against the team with the dead fucking last PP in the league in the regular season. Btw want to know how many PP goals Nashville scored in their 6 game series? Nada. 0 for 15.
And for all that, the Finals went 7 with the 2nd best team in the league versus the hottest team in the league in the 2nd half of the season and into the playoffs. They may have redid the bracket challenge, but I wonder how many people would have picked Caps/Pens in Round 1 if we hadn't played each other 3 years running in Round 2 and won the last 3 Cups versus just basing it off how the actual teams played this year and how their opponents did.
TL;DR Many of us picked too much chalk from previous years, and not based on this year (and especially how teams played going into the playoffs). Throw in the usual hot goalie/bad match ups in certain series...you get a good number of lower seeds beating higher seeds, but nothing I'd dub a HUGE upset outside of Tampa losing how they did.
