Board Thread:Questions and Answers/@comment-12794005-20131013131100/@comment-26808654-20140805050802

^ One, I believe there's a legal issue (could be wrong though). Two, I think Sonic Team is trying to stay away from romance. Elise was a fail and the fanbase is at war with itself already. If they bring back Cosmo to be with Tails in the game continuity, it will tick of Tailsream fans. Not to mention, it'd just be weird to have Cosmo in the games.