The new BattleToads game teased at Microsoft's E3 this year said it'd be out in 2019.
However, the next Xbox Console is rumored to be out in 2020, and would need some enticing launch games.
The new BattleToads should be one of those games, as it's not the kind of game often seen on Xbox, and it's a relaunch of an old Rare IP people have clamored for in the past decade or two.