Although there's been no confirmation by EA, I think we've all just assumed that SkyHeroes was the last game and that MySims is over.
As much as we all would like to see MySims return, right now I think all we're gonna get is cameos.
It's sad...but hey some character actually made a camoe in The Sims Mobile I saw Candy and Poppy in the Trailer https://www.youtube.com/watch?v=bmNVt5B4rSY