Every Spider-Person to appear in Spider-Man across/beyond the Spider-verse.

Miles Morales

As the main character fro the Spider-Verse Trilogy, it is 100% he will appear in Across the Spider-Verse. In the most recent trailer, we see Miles has a technology suit, probably designed by Ganky Lee who hopefully we will see more of in this film. He was great in the Spider-Man Miles Morales game.

Gwen Stacy

Also as the supporting role in the Spider-Verse Saga we will 100% be seeing the ghost-Spider in newer instalments of the Spider-verse films. In the 20min trailer shown at cinecon we see Gwen Stacy's dad, Captain Stacy.

Spider-Man 2099

2099 is the latest instalment to the Spider-verse trio, being the third character to be played by Oscar Issac, he seems like a big part creating the device to go through realties.

Scarlet Spider

As shown in a leaked board game for the film, we know now that he will probably be a big character, considering himself being the fourth person you can play as on the board game.

Peter B Parker?

There has been some confusion about if Peter B Parker his returning or not because he has appeared on some action figures, but if you look closer you can see that it is based of Spider-Man into the spider-verse, not across.

Spider-Punk

As he appeared in a jigsaw for the film, it is definite he will appear, hopefully rocking out with his signature guitar from the comics.

Cyborg Spider-Woman

Also appeared on a jigsaw and an action figure, Cyborg Spider-Woman will definitely appear. This will probably be a hybrid of Spider-Woman and Cyborg Spider-Man.

Spider-Woman

Jessica Drew has appeared in the 20min trailer for the film, this will not be the ultimate universe, as she will be pregnant through-out, hopefully giving birth to Spider-Baby: Gerry drew.

Peter 1, 2 and 3

Tom Holland, Andrew Garfield and Tobey Maguire have all said they are not returning, but that has happened before with No Way Home, so we could see them?

Spectacular Spider-Man

I really have know proof for this but I just want a Spectacular Season 3.