And like who would be more deserving than Porky?
Below I'll name each game in the series, the best picks for characters, and explanations as to why.
MOTHER
Ninten
If Sakurai finally decided to put an original MOTHER rep in the game, it would obviously be Ninten. He is the main character of the game, but would be extremely similar to Ness in appearance, moves, and everything. He would be almost an exact clone.
EARTHBOUND (MOTHER 2)
Jeff
Jeff is one of the four main characters used in EarthBound, so he actually fights. What is unique about him is that he uses non-PSI attacks. It would be interesting to see a non-PSI rep. Plus, Sakurai put him as an Assist Trophy, so that is a boost in my opinion.
Paula
One of the other four, she is unique and she would be another female fighter, but she uses PSI powers, so that would make three clones (we saw that in Melee with Doc, Mario, and Luigi, but Sakurai probably wants to avoid that). But, she is still a very recognizable Earthbound character and would be a good choice.
Poo
Probably tied with Paula, but I still think Jeff is a better choice. Thats all I have to say about Poo.
MOTHER 3
Flint
The father of Claus and playable for some parts of the game. He is actually playable in the game, unlike Porky, and Sakurai may want to stick with the playable in their own game factor. Plus he is vital to the game, is recognizable, and he is another non-PSI rep. He would be a better choice.
Kumatora
Once again, a possible clone with her PSI powers, but she's playable and a very deserving character.
Duster
Playable in the game and he does not use-PSI powers. He wouldn't be as great of a choice as Flint or Kumatora.
Claus
Lucas' brother, obviously. Claus isn't playable for pretty much the entire game, but I've heard you fight with him at the end, which is even more than Porky did. Plus, Claus is a familiar character and is VERY important in the game. He is far more deserving than Porky, and Claus is the last on the list!
See all these PLAYABLE characters that are more deserving than Porky? Sure Porky fought and he's important and everything, but you actually fought as these people and they have qualities that make them way more deserving than Porky.