There is speculation that Super Mario Maker 2 will not have amiibo support. Reddit user realestmemoryman3 posted on the Mario Maker Reddit a link directed to a Gamefaqs thread. In the thread, there were comparisons of different first-party Nintendo Switch Game posters including Super Smash Bros Ultimate, Yoshi's Crafted World, and Captain Toad: Treasure Tracker. On all posters of the respective games, there are amiibo logos on them. However, there is not an amiibo logo for Super Mario Maker 2.

You can see comparable examples below:

Super Smash Bros Ultimate:

Super Mario Maker 2:

In the original Super Mario Maker, you could use specific amiibos like Link from The Legend of Zelda or Marth from Fire Emblem to transform Mario into the respective character in sprite form. Mario would get this form by picking up a mystery mushroom. The 30th Anniversary Mario amiibo, if used, would spawn a Big Mushroom power-up to make Mario gigantic.

While we do not know for certain whether or not this information is true we should find out soon. The game is set to release at the end of June and with E3 being right around the corner we're likely hear more about the game soon. There are a lot of new features coming to the sequel that we have learned since it's announcement in February this year. There is also speculation that there will be multiplayer in the game due to the official site having "TBD" listed under players. We will not know the truth until Nintendo announces new information or until the game's release.

Super Mario Maker 2 releases June 28 exclusively on Nintendo Switch and can be pre-ordered on Amazon.