Alright, now we know it's not easy to stuff the ballot box. Although this is already late - How about saving your thumbs?
If you're still patient after reading that, then it's time for my speculation:
Take a look at the rule, that made me suspect their true intention, again. There are no special restrictions, but the final decisions will be Nintendo's.
Think about the possibility they already decided additional characters prior to the launch of the game. In this case, the vote serves as a way "to get to know the players better" and to find out possible characters they overlooked in the first place.
If happen to be right, then no matter the outcome will be, every nominated character has a chance to join Smash (might not as a playable, though).
Soon time will tell.