Adventure Quest 3D is a cross-platform MMORPG available on Steam, Android, iOS and other devices and we could be seeing it on Nintendo Switch in the future. Reddit user JCWOlson emailed the developers behind the title and in their reply, they stated that they would love to have the game on Nintendo Switch and that the team is currently looking into porting it over to Nintendo’s latest console.
Adventure Quest 3D Devs Would Love To Have The Game On Switch

A good deep MMO is way needed on Switch, sadly I’m not sure this is the answer…
Someone should make something like that with local wireless co-op as well for when out of the house.
Jagex said that RuneScape would fit perfectly on Wii U, and said to be checking it out. But I think the official reason was that they blamed a poisonous community for stopping the project.