I don't think BH will come back to the band...obviously (at least at this point in time) it's not about money for him, or else he wouldn't have left in the first place...and like someone said, he is really cool to his fans and I don't think the whole "fuck you, fuck you, fuck you" attitude\actions of GNR appeals to BH that much...it was fun while it lasted I'm sure...
I dont think it makes buckethead very happy either when shows get cancelled , without explanation , and kids are hurt during the ensuing ensuing riots.
Another thing to think about is maybe upon hearing the lyrical content buckethead made a decision that the material/lyrics werent something he wanted to associate himself with.
But again , I will/would feel really damn good if Bucketheads parts remain regardless of the fact that he may not return. GNR should try make an effort to put forward the best music possible regardless of who playing and what his/her status is in the "touring" band .. release the best music possible and worry about how to present it live afterwards.
peace all!