I first heard rumblings about a potential Garber exit last spring as Legends of Tomorrow was wrapping its second season. The chatter intensified over the summer. While no one would comment, a pending departure was inadvertently revealed in early September when it was announced that musical theater veteran Garber would return to Broadway, teaming with Bernadette Peters to headline the Tony-winning revival of Hello, Dolly!, taking over from David Hyde Pierce and Bette Midler. Their first show is on January 20.
I hear he will remain series regular on the current third season of Legends Of Tomorrow though there are no current plans for him to return for further episodes.