You know, just now it dawned on me why I feel happy about this right now, even if it's not actually Skull Kid so we won't hear the announcer announce him as such.
As I said before during discussion of the possibility of Majora's Mask being a fighter instead of Skull Kid, when I consider what characters I want for Smash, "they'd have a cool moveset" is never top priority for me it's important, but it's never the primary reason I want a character). What matters to me is how much I like the character—their personality, their backstory, and generally the traits that endear me to them as any character. I love Mewtwo, my original most wanted, for his personality, his design, his backstory, and his character arc (design though taking a backseat to the others). I love Skull Kid for the same reasons. A character I adore can get in Smash and have an entirely unfitting/ineffective moveset, and while it would be awesome to have a fitting moveset, I would still play as them. It's who a character is, what their story is like, what endeared me to them in the first place without even thinking of Smash potential, that has me want a character in Smash.
Do I want Skull Kid with a fitting moveset? Heck yes absolutely! Is this good enough? Nah, I still want him to be properly playable. While the moveset may not fit as much as it could, the Mii costume looks exactly like Skull Kid, and thus I can at least somewhat get that sense that I'm playing as him, rather than a costume of him. It's definitely a step up at least and has me think he has more of a chance in the future than I first thought.
My original most wanted returned, and my new most wanted is at least in in a way that's decent enough to be believable for me (shame about no moveset but it's better than nothing). While I really hope that we can get Skull Kid in as playable himself in the future, either as DLC for Ultimate (there's 30 free character ID slots after all so he still has a chance) or in the next game, I'm reasonably content with this outcome, for the time being.