hellooo it is me, the famous accurate Nintendo leaker and I have seen a reveal trailer for Fighter 9, which is Cinderace. Since I can't show it, I will reiterate it for you:

Trailer starts:

Sakurai is emotionally drained. A representative from Nintendo knocks on his door and comes in.

Nintendo says they want Sakurai to add another Pokemon to Smash

Sakurai begs them not to force him to add another Pokemon

Cinderace then breaks down the door to Sakurai's office and hands Sakurai some choccy milk. After Sakurai finishes his milk, he hands Cinderace a Smash invitation

Cinderace serves up a battle!