The Super Mario Maker 2 Direct has confirmed that there will be co-op making in the new game. During the creation portion, someone could take the second Joy-Con and pass it to another player. The two people can then work together to create a course.
When Super Mario Maker 2 co-op making is in effect, each person has a hand in creating the level. Everything takes place on the same screen, with no split screen option. The two people each have access to the same palette of tools. You can even set a Multiplayer Versus tag to levels created in this way, for the other sort of multiplayer mode.
In addition, in Course World allows competitive and cooperative multiplayer with other people. You can play as Mario, Luigi, Toad, and Toadette in either Multiplayer Co-op or Multiplayer Versus in Global Play or Nearby Play. Up to four players play against each other in the competitive option, facing off in a randomly selected course. You are assigned versus ratings, depending on how well you do. (The first person to clear a course wins.) In co-op, the goal is to work together to complete the level or course condition. Everyone wins if one does. The course difficulty levels are Easy, Normal, Expert, and Super Expert.
The Nearby Play was also discussed. When up to four people are together, one will set up the virtual room for everyone to join. Only this one person needs a persistent internet connection. This mode is unrated and unranked, though you can see how each person is doing in unofficial standings.
In addition to Super Mario Maker 2 co-op making, a number of other new features were shown in the New portion of this Nintendo Direct. The Angry Sun and Banzai Bill appear as new enemies. (Banzai Bill has a homing option.) People can create custom scroll options in levels, determining the trajectory or speed. There is a Snake Block, with a faster blue option. Swinging Claws can be placed. You can make Vertical Sub-Areas. You can also create areas with water (or lava) levels that change their height at up to three speeds over time.) This is in addition to the already confirmed slopes. The game will also allow you to set Course Conditions for stages, making people reach certain requirements like having Mario with a certain power-up to win.
Super Mario Maker 2 will come to the Nintendo Switch on June 28, 2019.