Board Thread:Speculation, Theories, and Rumors/@comment-26267047-20150401180018/@comment-679780-20150402173334

Ultrasonic9000 wrote: It would be nice to see Blaze, but unfortunately, Bill Freiberger has confirmed no other game characters will appear. It season 1, still early days.

Still I guess no point getting hopes up. AoSTH and Underground didn't raise the bar much with just Dr. Robotnik, Tails and on the occasion Knuckles in Underground.

The right characters could still make interesting episodes in the right theme of it. For example, an episode could be about Sonic and his friends dealing with a rival team of heroes called Chaotix who try to get Knuckles to join their team.