From what I’ve read in official video descriptions, the game can also be purchase as an expansion to A.O.T. 2.
☆ NintendObs Weekly – Monday, April 8, 2019 – Sunday, April 14, 2019.
…Wanna play? Buy a Switch.
And if you’ve already got yours, click on Attack on Titan 2 Final Battle for everything you need to know about the game. 😀