Yeah he later mentions in the thread that the leaker he cross references seems to think it's a Dragon Quest rep for Square Enix:
"
I did not say anything about me being almost sure that the Square Enix character is a Dragon Quest character. I brought up that LeakyPandy heard the Square Enix character would be DLC (something we both wound up hearing) but he also heard that they would be revealed at The Game Awards and hinted at it being from Dragon Quest.
I am not backing what they are saying in bringing something to attention that people may not be aware that they did.
I'm not going to list off the Square Enix character names that I heard the character is being spread around to be by Square Enix themselves to stamp out leakers within their company since they have an intolerant stance against them. I gain nothing from doing that if the character someone really wants for instance is among those names and not it, then somehow I am the a****** to blame for them not actually being chosen and will be harassed because it isn't who they wanted.
Not to mention it putting people's jobs in jeopardy at Square Enix because they will fire people under suspicion alone. Even if they did nothing wrong. I don't want to deal with any of that and the issues that come from saying the Square Enix character names it has been said to be. Sorry. " - Vergeben
Source:
https://gamefaqs.gamespot.com/boards/234547-super-smash-bros-ultimate/77160319/911668687