Keiynan Lonsdale explains the reason for his exit from the Arrowverse, since he won't return as a series regular on Legends of Tomorrow or The Flash. It's simply because of the actor's own desires. Lonsdale, who plays Wally West, will not return as a star on either Legends of Tomorrow or The Flash. The move came as a bit of a surprise and a disappointment as Lonsdale and Wally had one of the best arcs of any Arrowverse character during the previous season.
Lonsdale entered the Arrowverse as a series regular on The Flash during season 2. However in the middle of The Flash season 4, the actor moved over to Legends of Tomorrow as a series regular (with just a quick appearance in The Flash's season 4 finale). Now Wally and Keiynan will be moving on from the Arrowverse, but the actor promises he'll make a return when Wally is needed the most.
The reason for Wally's exit isn't because of any story reasons or behind-the-scenes drama with Keiynan Lonsdale. The actor has simply explained that he's changed and would like to move on from the Arrowverse. In a lengthy post on Twitter, Lonsdale explained that his exit from the Arrowverse isn't "a total goodbye or a 'see ya never'" type of situation. Wally and Lonsdale just won't be around full-time on any Arrowverse series. The actor writes:
I've changed a lot in the past year ... and for infinite reasons my perspective on life and what I want from it is just completely different. Because of that my heart told me it was the right time to continue my journey on an unknown path, and I'm so damn grateful to both shows for honouring and respecting me with that.
Love you all ⚡️❤️ - Keiy x pic.twitter.com/JBdxUaKocA— Keiynan Lonsdale 🌈 (@KeiynanLonsdale) June 6, 2018
This type of exit, while sad for fans of the character, isn't all that unusual. Usually the big exits from the Arrowverse come about in a much more permanent way. Paul Blackthorne was removed as a series regular during Arrow season 6 because the actor wanted to move on and his character, Quentin Lance, was killed off in the finale. Yet from Lonsdale's message it doesn't sound like Wally is going to be killed in his final Arrowverse appearance (for now) during The Flash's season 5 premiere.
Wally will probably go off on some new adventure or maybe even quietly retire from the superhero life. This way the door is always open for Lonsdale to come back. It's a departure that has been offered to previous exiting Arrowverse cast members. Franz Drameh's Legends of Tomorrow character Jefferson Jackson retired back to his own time during Legends season 3 but reappeared during the season finale. Meanwhile, Willa Holland exited Arrow as Thea Queen during season 6 by going off on a new adventure with Katrina Law's Nyssa al Ghul.
Lonsdale claiming that Wally will be back (eventually) might seem like a hollow promise, but there's precedence for that as well. Colton Haynes exited the Arrowverse as another superhero sidekick, Arsenal, during Arrow season 3. However, now Haynes is returning to Arrow season 7 as a series regular, once again playing Roy Harper. Hopefully the wait for Lonsdale to return as a series regular won't be as long as the one for Haynes. Yet it definitely could happen that Wally will be a regular member of an Arrowverse series, whether it's Legends of Tomorrow, The Flash or something completely different.
Source: Keiynan Lonsdale/Twitter