Rumor: Super Smash Bros. Ultimate Mii Costumes from DOOM & Super Mario RPG Leaked

A new rumor comes to us, although this time it is not about Pokemon Sword and Shield, but about Super Smash Bros. Ultimate. The GameXplain YouTube channel has shared a video, which explains the alleged leak of new Mii costumes for the game.
This video has a link to another where you can see a Mii character with a DOOM Cacodemon hat and another one with a Super Mario RPG Mallow hat in Super Smash Bros. Ultimate game.
You can watch the video below:
Here are the video and image (at the top of this article) to which it refers:
As always, this has not been officially confirmed, so we recommend you take this information as what it is, a rumor.
What do you think about it? Tell us in the comments below.