Hi, Mona Fans, WarioWare Fans, and Wario X Mona Fans, Ewan Dewar said there's a website we should use to contact Nintendo to help Support Mona especially to appear as a Costume in Super Mario Maker 2: https://en-americas-support.nintendo.com/app/ask/ht/299/cp/599/mq/332

and Also another link, This as an option for contacting the enquiry: https://developer.nintendo.com/contact

Spread the word, Thank you all especially Ewan Dewar, You're all rock