It's worth paying attention to the history of the Big Band era and it's associated Swing period, which dominated the musical taste of America from the early thirties until WWII brought about its decline. Therein lies the lesson: Everything dies. Swing gave way to Bebop gave way to Jazz gave way to Blues gave way to Rock and Roll. And today? The doom of Rock is likely upon us.
This isn't necessarily a bad thing. Rock music's back catalog has serious problems in the here and now. Try singing any random Zeppelin song in public -- You're gonna get some pretty irritable looks. The soul of a woman was created below? Let me know how that goes for you.
I don't particularly worry all that much about the decline of guitar based four / four music because the implosion of the record industry combined with the freedom advances in technology provides ensures that whatever type of music you enjoy will be getting made for as long as there people anywhere making music. Swing bands are a perfect example of what I'm talking about, but it applies equally down the line. All you have to do is dial it up.
Boswick's players are a fine bunch. Stretching back to the late seventies as an organization, they're as much an institution as a band. They serve a needed role as curators of a fading form. If that was all they did, it'd be a win. But they got the people here dancing as well. Which is what Swing was born to do.