Digimon Story: Cyber Sleuth originally released exclusively for the PlayStation Vita in Japan in 2015. A PlayStation 4 port was released in Japan, North America, and Europe in 2016 alongside the Western release of the Vita version.
The four Digimon games released in the West before this -- Digimon World DS, Digimon World Dawn and Dusk, and Digimon World Championship -- were all released for the Nintendo DS. There were also several games exclusive to Japan, such as Digimon Story: Lost Evolution and Digimon World Re:Digitize Decode, released on the Nintendo DS and Nintendo 3DS, respectively.
It might seem weird to bring the Pokémon rival back to Nintendo consoles, but with games like Monster Hunter Stories and Yo-Kai Watch 2: Psychic Specters already out in Japan and coming to the West soon, Nintendo is no stranger to monster collecting RPGs that aren't of the Pokémon variety.