Season 3 of Sonic Boom (TV) was deconfirmed according to Wikipedia

Sonic Boom Season 3(Ponypainter09), Sonic Fanon Wiki

Sonic Boom (TV series), Sonic Wiki Zone

Street Fighter (universe) - SmashWiki, the Super Smash Bros. wiki

The disaster that is Sonic Boom. The most unfinished game in recent…, by Vidya History

Sonic the Hedgehog, The Sonic Boom Wiki

Which is one of the fastest heroes, The Flash or Sonic the Hedgehog? - Quora

Sonic-16 (non-existent build of unreleased Sega Genesis/Mega Drive game based on Sonic the Hedgehog animated TV series; 1993) - The Lost Media Wiki

Sonic the Hedgehog CD

Sonic Boom (series), Sonic Wiki Zone