If they haven't had a problem with it up til now, I think it was a premptive strike against the left, who might give the band a hard time for 'allowing' Rush Limbaugh to use their song. As we all know, if the license is purchased, there can be fair use made of parts of songs, but the libs want to make a stink to keep the issue front and center.
From what I saw, a Leftist blogger named Bob Cesca on the Huff Toast contacted their management and said “did you know your music is being played by Rush Limbaugh.” He wrote about it.