When I've gone to see GNR in the past, they'll put on like a 3 hour show. Extended jams and solos are thrown in between songs during the set. And they'll even have someone else in the band take a song or two on vocals, typically a cover tune or something. That's where I'd imagine this would get played, if it happens at all. And if that happens, does it lessen the meaning, because Axl wasn't there to"pay tribute"?
Who knows what happens? I just have a hard time believing that Axl would be the one to be out there singing it. Then again, this whole "reunion" and AC/DC thing has yielded plenty of surprising Axl moments.