It be to do with the Electric Flower, seeing the way things had been with it much like the Bubble Flower, more details can be explained in this petition here: https://www.change.org/p/introduce-an-electric-flower-power-up-to-the-mario-series-in-his-next-2d-game

Right now I can only hope that Super Mario Bros. Wonder won't be the only game ever to have the power ups introduced in it, so they can join the list with what's in this petition, especially if there being a Switch 2 Edition stops the game from having a direct sequel of any sort.