The Arrow-verse will look quite different in the next season, and not just because Nora West-Allen is on the scene, Oliver Queen is in the clink, and John Constantine is taking the Legends through mystical adventures. No, another change will be the absence of Keiynan Lonsdale as Wally West, who jumped from The Flash to Legends of Tomorrow in the 2017-2018 season. Lonsdale's on-screen sister Candice Patton was asked about saying goodbye to him at San Diego Comic-Con, and she had this to say:
I don't want to. I love Keiynan so much. If anyone knows us, we're very, very close, and that was a hard one for me. It was hard saying goodbye to Rick, it was hard saying goodbye to Keiynan. And he's not gone forever; he's just not there a lot. But yeah, I think it had the potential to be a great character, and I think it is a great character. I think there's so much more meat to pull from Wally. He's such a beloved superhero in the comics. If you're a fan of the comics, Wally is such an incredible character. And I think Keiynan brought a lot to that character. So yeah, he'll be missed in The Flash world. He won't be there all the time, but he'll resurface every now and again, which...you know, I'll take it. I'll take it.
CinemaBlend's TV Editor Nick Venable asked Candice Patton about her feelings regarding Keiynan Lonsdale's departure during roundtable interviews at San Diego Comic-Con, and she seems to be banking on her TV bro returning to the Arrow-verse at some point. The Flash cast is clearly tight-knit, and losing Lonsdale -- even if it was due to his own decision rather than getting killed off or sent out of the Arrow-verse against his will -- isn't going to be easy. Sure, he wasn't around The Flash as much once Wally took his break from Team Flash and then shifted to Team Legends, but he was still around, and there's always the chance for crossovers in the Arrow-verse.
Keiynan Lonsdale spoke out about his decision to leave the Arrow-verse, and he made it quite evident that there's no bad blood that led to him moving on from the superhero life. The actor made a splash in the mainstream thanks to his role in Love, Simon, so he could success sooner rather than later on the big screen or perhaps elsewhere on the small screen. The superhero life isn't for everybody. Besides, maybe he could come back in a few years to recur. If Colton Haynes can return to Arrow, why can't Lonsdale return to Flash or Legends if he so desires at some point?
A big question now is how The Flash and Legends of Tomorrow will write Wally West out of the shows. Legends has the habit of bringing characters in and out of the action, so there should be less of a problem for that show than The Flash. Wally actually sped onto the scene in The Flash Season 4 finale to celebrate the birth of his baby sister (and inadvertently meet his niece from the future). The Flash will have to explain his sudden disappearance. At least The CW has confirmed that Wally won't be killed off!