Alright, let's put this to a vote: Do you think Eggman will come back in movie 4?
So, Jim Carrey has said that he would be willing to come back for a fourth movie provided the script interested him, meaning that there IS a chance that he could show up again to play Eggman, and the mid-credits has confirmed Metal Sonic as a major part of the next movie, a character with heavy ties to the character.
HOWEVER, the fourth movie will also happen after we saw Eggman heroically "sacrificing" himself to save the world, leaving his fate extremely ambiguous, so it's also opened the door for Eggman to NOT come back immediately if the creative team choses to go that route. Plus it's possible they might want to try and switch things up so that that they don't have the same villain four movies in a row.
So what do you all think?