There are currently no plans to make Sonic Adventure 3 and continue the Sonic series from the Dreamcast days.
Sonic Team boss Takashi Iizuka was interviewed by VGC and discussed the possibility of continuing the series, as well as a return of its much loved Chao Garden.
Iizuka acknowledged the requests for the Chao Garden to make a return, but noted “it’s part of the whole Sonic Adventure series game”.