I did see the Sakurai tweet earlier and I've been getting worried. Surely one of the characters chosen is likely for marketing purposes (hopefully not Fire Emblem *shivers*), and I do hear all the commonly popular characters wanted and whatnot.
And here I am just hoping KI's Medusa has a chance, but I also look at Monster Hunter, which does have a chance. Yes I know the latter did have Mii costumes in the past, but this wouldn't be the first time a "character as a Mii costume" eventually became an actual character (Looking at you Inkling and K.Rool). At the same time, I'm sure MH has had quite a bit of time on Nintendo systems. However, I won't get my hopes up, but I'm also aware that they are possible to be part of the upcoming DLC. I hope at least of em comes true, but at this point, I'm leaning towards MH to give a new series to Smash some love.