The terrible twos aren't terrible at all when you're talking about Killer Instinct. The Xbox One launch title celebrated its second birthday over the weekend, and its future looks promising. Season 3 drops in March, but before then, Shadow Jago and updates to the HUD are coming.
Iron Galaxy promised Shadow Jago would join the roster with his own moveset by the end of the year. That's still the plan. The latest word is "not too late" in December.
As for the HUD changes, they'll arrive in title update 2.12 and are geared toward providing players and commentators with more information. Expect better visual feedback for things like reversals, combo breakers, and lockouts (as well as punishments, but not until update 2.13).