It doesn’t matter what you do after Star Wars, there will always be people who ask you about the franchise and your willingness to return to it, and if the last 6 years as shown us anything, it is that Disney is not afraid to go back to the well to bring back popular past characters to expand the universe more.
While promoting The Last Letter from Your Lover, Jones was asked about her willingness to return to Star Wars if the opportunity presented itself to which she replied, “Never shut the door on Jyn Erso, never!”
The main issue with Felicity returning to the franchise is that it would have to be in pre-Rogue One content, because most people that have seen Rogue One assume that both Cassian Andor and Jyn Erso died in the massive explosion that engulfed both of them at the end of the movie. I say most people because of the quote from Felicity below.
“I was having this conversation with someone the other day, and I was trying to say, ‘It’s a bit of a nuclear fallout at the end of the film. And they were like, ‘No, it didn’t feel like that, it doesn’t feel like they die.’ And I was like, ‘Well, there you go. There’s a chance of a comeback.'”https://www.digitalspy.com/movies/a37163204/star-wars-felicity-jones-jyn-erso-return/
Not sure how anyone can watch that scene and assume that those characters survived, because, in my opinion, the huge fireball that literally engulfs them at the end of the scene pretty much confirms they are dead. But, we all know that death is only final in Star Wars about 60% of the time.
In all seriousness though, the best avenue for a Jyn Erso/Felicity Jones return would be through the Andor Disney+ series that is filming now. There would have to be some fiddling with the story to make that happen since the first meeting between Jyn and Cassian happens in Rogue One, but I’m sure there can be some side plot or complimentary scene with a pre-Rogue One Jyn running around the galaxy messing with the Imperials.