The early deal to bring him back for Now You See Me 3 is viewed as a vote of confidence from Lionsgate that the sequel will do well.
The first film in the franchise was directed by Louis Leterrier. Lionsgate planned for a third movie soon after the second went into pre-production. Jesse Eisenberg, Mark Ruffalo, Woody Harrelson, Dave Franco, Morgan Freeman, and Michael Caine all return for the sequel with Lizzy Caplan and Daniel Radcliffe joining the cast.
No time table for Now You See Me 3 was given - after all, there's still a whole other movie to debut first.