This is the roster I think will have a good chance of making it in the game.
Bandana Dee:
I know some people have a problem with him. However I find him fine, and is the best choice for the 4th Kirby Rep. He can have a unique moveset that uses spears, or potentially he could summon all of the enemies that Kirby fights thoughout the games. His appearence in the 2015 Kirby game, (Kirby and the Rainbow Curse) proves that he is more than just a generic Waddle Dee.
Ridley:
It's Ridley.
Chorus Kids:
We saw an enemy from Rhythm Heaven in smash. I say that Chorus Men have a huge likely hood because of that reason.
Shulk:
I know squat about Shulk or his series, he is kind of a padding character for me. I have no opinion of him.
Cuts:
I'm confident that Snake, Ivysaur, and Squirtle are the only cuts. Maaaybe Lucas, but I REALLY don't like that.
I'm thinking that there will be 3 trailers in the August direct:
1. Wario and Chorus Men reveal plus a random veteran like Ice Climbers.
2. Shulk and Falco vs Ridley and Ganondorf.
3. Bandana Dee, Jiggs, and Meta Knight trailer.
Also I think that Ness or Lucas will be revealed during the final day of Comic Con San Diego as that is the anniversary of Mother 1.