There have been countless arguments about GNR being played on modern radio when they release the singles....
As you all know U2 released thier single yesterday. Krock in Ny has been playing the hell out of the song. In fact they play it at the top of every hour. They have also played a full hour of U2 during thier request lunch program. They also have countless prize giveaways and promotions regarding U2.
My point is that GNR will have no problem getting a chance on the modern radio format. Of course the single has to be up to standards but they will be given the chance.
I don't think gnr will have problems getting airplay. Even when inactive, they get more press than most active bands