>>545962328
let's see...
there was 12 riders in the demo but 20 riders (that we know of) in total, there's 23 machines (27 if we count the whale, legendary machines and flight warp star, not sure what the deal is with the whale yet)

so there's a possibility of 3 (or 4 if the whale is a normal machine) more characters if they want to pair every amiibo with a character.

and that's not factoring in any updates that may or may not happen (sakurai said no but animal crossing said the 2.0 update was the "final update" so never say never)