April 26th 2019 is believed to be the day of the game's release, we shall find out for certain hopefully in a Nintendo Direct of some kind that'll take place in early 2019. While that may also seem like a good time to for Ultimate to have itself a DLC Stage from Yoshi's Crafted World at that time, Spring 2019 is likely when the DLC with Joker and the Persona 5 stage will arrive, but there's still hope for a stage based off Yoshi's Crafted World coming around eventually, thus leading to another familiar franchise have both new and familiar stages in Ultimate alongside Mario and Zelda.