https://www.cbr.com/lando-star-wars-spinoff-plans/
Despite all the rumors of an Obi-Wan movie that seem to resurface every few months, it looks like this might be the next film. Given that the stars are also possibly signed for a multi-picture deal (I'm sure Han could pop in some way), a "Solo" semi-sequel kind of makes sense.
Maybe it'll deal with how Lando won Cloud City and met Lobot in some way (Not sure if that would contradict anything in his REBELS appearence)? Or like Solo perhaps shed some more on the character's background?
I wouldn't even mind a "present day" sequence with Billy Dee Williams that could maybe explain why he isn't in the sequel trilogy.