let me put it another way... say there is going to be a smash 5 for the next console after Wii U... Smash 5 is announced without sakurai's intent...
what are we left with in terms of new characters? crap.
you can conserve.
I don't get this statement.
It sounds like you're saying if Sakurai isn't choosing the characters, there'll be terrible character choices.
Character choices are purely subjective. Though judging by the type of characters that have been introduced in past games, you can more or less tell what a "good" character stands for.
Example:
Pit (main character)
Olimar (main character)
ZSS (main character, different attire and moveset) ((not very well received though))
Sonic (main character)
Snake (main character)
Lucario (pokemon generation rep)
Pokemon Trainer (main character of Gen 1 pokemon)
Wario (former main enemy, main character of warioland/Warioware)
Lucas (main character from Mother 3)
Ike (main character from FE9)
Wolf (main character's rival)
Metaknight (main character's rival)
Dedede (main character's villain)
Diddy (main character's sidekick)
So, in my opinion, a GOOD characrer choice would be one that
a.- is the main character (very good choice)
b.- is the main villain (good choice)
c.- is a supporting role for the character (mildly good choice)
There are exceptions. I have mixed feelings about ROB because he doesn't have a game where he IS the main character. But he IS iconic to Nintendo in a way... And cameos of him have been recurring since the 90's.
Anyway, this is just my opinion.
Waluigi or Bowser Jr, for example are not very good character suggestions because both are... Main enemy's supporting character. (I do approve of Bowser Jr. but I don't think he'll be an ideal character choice)