In my years of writing about hockey and doing playoff previews, I have seen the Blues as underdogs many, many times. I myself have felt that the Blues were the underdogs probably close to just as often.
But good Lord, I have not seen probabilities and doom predictions like this in my life. MoneyPuck.com has the Blues dead last out of all teams to win the Cup, with only a 15.6% chance to make it out of the first round alive. No other first round matchup is that clearly lopsided. Dom Luszczyszyn over at The Athletic (subscription required) has a worse outcome predicted for the Blues with only a 12% success rate.