Well at the banquet last night, Dave Snell mentioned how Coach Les had taken a Bradley team farther than any team since 1954 (or so.. I think he said it 52 years ago), so it would make sense for BU to put up some banner for something that hasn't been done in over half a decade.
Lots of other schools have Sweet 16 or Final Four and other accomplishments banners in their arenas.
And obviously they will put "2006" under the other 7 years on the red "banner," if you can call it that.