This is my current predictions for the game:
1. The game will use the same framework as the original game. It will just add on to it.
2. All of the veteran fighters will return.
3. There will be 7-10 newcomers. Three of them will be Jimmy Neutron, Squidward, and Zuko.
4. There will be more modes, particularly for singleplayer.
5. The online section will receive a complete overhaul, with crossplay being included from launch.
6. There will be some sort of collectibles to keep players invested in the game.
7. Some new moves will be introduced, whether they are final smashes or just new specials is unknown.
8. Lincoln will receive new voice clips with his new voice actor or actress at the time this game comes out.
9. There will be some minor touchups, but overall the movesets of existing characters will not be tampered with.
10. The gameplay will mostly be the same as the original.