Arrow And Legends Of Tomorrow May End After Their Next Seasons
Nothing remotely concrete then...
I wuldn't be surprised if Arrow was going to wrap up come Season 8, especially since Crisis (may) result in a sacrifice by Ollie, and what with the flash forwards, we kinda' know that Ollie's mission to save his city is going to take a wrong turn at some point, and everything is going to go to hell. Kinda' reminiscent of what happens in Gotham when Batman isn't around - the criminals go to work.
Legends is also said to be expensive for what it is, and with that ensemble, it's a lot of characters to write for. I wouldn't be opposed to Legends wrapping - it's had a damn good run, don't get me wrong, but if any show was actually going to wrap, I'd say it would be Legends because of it's cost. If Carlos, Danielle and Echo are indeed leaving the Flash and Arrow shows, that does potentially allow for three cast members to crossover, and you can easily move Ray and Nora (will that mean there's too many Nora's on the Flash) to help out at Star Labs.
I'm honestly not sure what they could do with Rory at the moment - wouldn't he return to a life of crime? I suppose he (could) reform the Rogues and be more an antihero group that gets along with, but also irritates Barry? Could be a fun dynamic to explore.
Sara, I'm at a loss really. No point putting her back on Arrow, we've got enough Canaries on that show already, and she's not involved in the future. Wouldn't specifically want her in Gotham either. Zari on the other hand [could] work on Batwoman as the techie? God knows what they're going to to with Constantine though.
It's all speculation at the moment in any case, just throwing ideas out there. One thing is for sure though, they're not ending Supergirl anytime soon.