I'd personally be up for a Shotaro only anniversary movie, just have him as Kamen Rider Joker and bring back Accel and we could probably get a fun film, but it probably wouldn't be worth it for Toei.
Yeah. It just wouldn't be the same. It wouldn't be an anniversary special of "Kamen Rider Double" it would just be some extra material with Joker.
Kamen Rider: Beyond Generations Movie Announced.
https://news.tokunation.com/2021/10/19/kamen-rider-beyond-generations-movie-announced-72173
This new film is titled Kamen Rider: Beyond Generations and will feature a special team-up between 1971’s Kamen Rider 1, 2021’s Kamen Rider Revice and a BRAND NEW Kamen Rider from the far-off year of 2071!
Kamen Rider: Beyond Generations is currently scheduled for release on December 17 2021.
And we got a sneak peek at the Kamen Rider of 2071 today
https://twitter.com/i/web/status/1457000007777718280

I'm getting Guyver vibes due to the antenna design. Now I'll be disappointed if he's not the star Kamen Rider when we actually reach 2071 much like i'll be disappointed if we don't get a ninja rider in 2022
