>>109751447I have a feeling Jasper went off and secluded herself somewhere after CYM, she no longer serves under the other diamonds since she reformed out of her diamond insignia, but if she started her redemption, or was living in little homeworld, or had gotten closer to Amethyst over the timeskip she probably would have appeared in that group shot during Amethyst's portion of here we are in the future. Maybe none of the other characters even know where she is.
In any case I think her current situation is being kept a secret for good reason but an in-show explanation for it and all her unfinished business is being saved for next season
