From what I understand, David Maslanka does not allow drum corps to use his music, so that would make sense.
Also, I know for a fact that Bertrand Moren adores what Crown has done with his music in 2012 and 2013.
And, finally, while Bernstein may have heard drum corps play his music, those who own it now absolutely HATE drum corps using it. In 2009, when like 10 corps used Bernstein's music-that was the last straw. The Bernstein Foundation now either wants A. the arrangement to be a direct transcription in order for it to be performed (essentially impossible in drum corps), or B. for the corps to pay an ABSURD amount of money in order for the music for be performed. In fact, I also know that this is the exact reason why Blast! no longer performs "Gee, Officer Krupke" or "Appalachian Spring" (Copland's music is also absurdly expensive).