Midway through a March Velvet Revolver gig in Glasgow, frontman Scott Weiland made an impromptu announcement from the stage. "You're watching something special," he said. "The last tour by Velvet Revolver." It came as a surprise to the other members of the band, who shared confused looks before launching into the next song on the set list: "Fall to Pieces."

As it turns out, Weiland was wrong: Velvet Revolver will tour again — but without him. After the show, the singer and his...