As a sequel? I don’t think so and I hope not in the chances that it ruins the things that made it great in the first place. But there could be chances of developing spin off films or series of that world if they don’t decide to blend it with Pattinson’s Batman universe

What I feel like they should do now after joker is to try and recreate this success with other iconic villains like reverse flash, Luthor, or other batman villains like riddler or Ra's Al ghul

I talked with the director and he said that he doesn't have any plans for a sequel but there might be one in the future.

Reverse Flash wouldn’t work like how Joker did as it’s something that’s not grounded with realism and more of a sci fi event^^

A reverse flash movie could show how deep respect and love can turn into extreme anger, hatred and obsession. In joker we saw society just crush someone until they finally break and with reverse flash we can see eobard's obssesion with flash slowly turning him from a scientist to man who is so deep in his hatred/ love for the flash that he rather become a living paradox then actually just let things go