Personally, if I saw the bill said BIG BAND, that's what I would have expected. I would have loved it.

However there are ways to incorporate newer material and STILL play it in the style of the Big Band. Or is that what is being objected to, the style?

I've heard Howie MacDonald and Ashley MacIsaac play showtunes in CB Fiddle style. It works! But it is in the style of the performer, not the original style of the music.