Just generally speaking, the "might as well, gonna lose him for nothing in expansion" argument is flawed. Seattle is taking someone no matter what. So if you get a lousy return for Dunn, you still lose a different player to expansion. The question becomes, is getting a 3rd and a 4th worth losing Dunn AND, say, Blais or Barbashev or Walman? If they really can't get a reasonable offer for Dunn, and they do expose him, that is probably a better situation than getting a 3rd + 4th and losing an additional affordable NHLer.

Now specifically in Dunn's case, the Blues would be dumb to get a crap return for him when they can simply leave Faulk unprotected and play chicken with Seattle. Which of Faulk's seasons do they consider the outlier? If the Blues were to lose Faulk, are they better off with the long-term cap flexibility? I'd say that Faulk lived up to his contract this year, but I'm not expecting him to perform at that level for 6 more years (and Seattle probably isn't either).

All of this might be moot because I think there are a ton of other teams that could use a protection spot on Dunn and could give up better assets: NJD, ANA, NYR, WPG, VAN, VGK (exempt from XD) etc.