Just last week, Blizzard doled out one of the biggest teases in recent memory, trumping a mere character preview for one of their several competitive offerings. They posted a Diablo nightlight and the words "Sweet dreams," leading many to believe that it was a confirmation of a Diablo 3 Switch port.
It's a joke that's been used a lot since the system was even first announced, but Blizzard stated that it was instead a "fun engagement piece." Blizzard isn't great at keeping things up wraps though, and a source for Eurogamer contends that a Switch port is indeed in the works.
According to their source it is "in production," though they could not confirm if it would include the Reaper of Souls and Rise of the Necromancer expansions/DLC. Yeah, I'd probably play it again as a Crusader or Necromancer on the go.
Sources: Yes, Diablo 3 is coming to Nintendo Switch [Eurogamer]
via destructoid https://www.destructoid.com/rumor-blizzard-is-allegedly-porting-diablo-3-to-the-switch-after-all-492998.phtml