According to a new listing on IMDb, Whitney Coleman and Kelli Barksdale are both stunt actors in the sequel, which is significant as they also worked on WandaVision. Coleman was Kathryn Hann’s stunt double for Agatha Harkness, while Kelli Barksdale was Jett Klyne’s stunt double for Tommy Maximoff.
Obviously, IMDb isn’t always accurate and even if it is, these individuals could be stepping in for other actors. But the signs are certainly pointing to the return of both Agatha and Tommy in Doctor Strange in the Multiverse of Madness.
Source: The Cosmic Circus