The answer is portability.
Atlus confirmed that Shin Megami Tensei 5 will be coming exclusively to the Nintendo Switch next year, which caused a bit of a stir among quite a few folk, not to mention surprise: the game, after all, is being made using Unreal Engine 4 (highly scalable across different platforms), and Atlus found great success with Persona 5 on PS4. Why skip out on that platform with SMT5, then?
The answer, as it turns out, is that Atlus views portability as a crucial element to the franchise at this point- but at the same time, they wanted to make a high end SMT game. The Switch ended up being the best of both worlds for them on that front.
In a recent Weekly Famitsu interview (via Kotaku), producer Kazuyuki Yamai discussed why the game is a Switch title. “I once realized once again as development was progressing that the Nintendo Switch is a compact piece of hardware on which you can play HD quality games, easily carry around, and that it truly a charming console,” he said, adding that the flexibility it provides to be played portably or on the big screen, is the reason Atlus went with the Switch.
This makes total sense, actually- and especially for a Japanese developer, developing for a Japanese audience, where portability is paramount. Shin Megami Tensei 5 launches on the Nintendo Switch… some time. We don’t actually have a date yet.