I'll be the foil then.
I'll put a bunch of my expectations in the basket just for fun because it's not like I could be disappointed at this point, the game is already pretty awesome from what we know so far.
Anyway, the last 12 or so minutes of the direct will go like this:
Game reveal (In my mind, Animal Crossing) -> Echo fighter from that game as transition into Smash segment (Isabelle, in this case) -> Smash Info -> "But wait there's more!" character reveal (Isaac).
I also always hold that the last curveball reveal may instead be a demo date instead of a character reveal.
Also, gonna jump the shark / grasp at straws here but while I'm putting a bunch of stuff on the table that I think would be cool if I got it right, Nintendo Online Service customers will be given access to specific demo events for future release titles. Importantly, Smash Bros. Dates for which will be revealed.
Thank you and be sure to totally ignore this so I can rub your noses in it when the hype dies down.
EDIT: 9/12/2018 12:20PM EST:
Giving it a little thought, I'm a bit more confident about it being Skull Kid than Isaac.
No further edits will be made to this post just so that when it happens, there's a time stamp on the edit.