Since RATM didn't really take hold in the Headliner thread I guess its out of the blue/unexpected.
After reading the CoS article, with that line about "Now that you guys are touring and playing together" statement in the interview I think it could be a possibility. Im not so sure it is "out of the blue" though, seeing as a 20th anniversary tour isn't a crazy idea. But it is certainly unexpected.
Maybe this is where Rage makes their triumphant return to the stage, kind of like what Eminem did in '11
Beck 7-8:30 > RATM 10-12 would be a pretty epic Saturday night
Die Antwoord --> Cypress Hill x Rusko --> Wu Tang Clan --> RATM