Squirtle
There is no need for Squirtle. There are plenty Gen 1 reps. Charizard is the starter rep. Greninja is the new water pokemon. His likelihood of staying in is
very slim.
Ivysaur
While there is no grass type (as of now) Charizard is still enough for a Gen 1 starter rep. I'm not really sure if I expect anymore starer pokemon, but if I do I don't think they would axe Squirtle alone.
Snake
He is a third party so it is easier to have problems with his return than Nintendo character returns. His newest game is for PS and Xbox so that has got to say something. With that aside though, snake doesn't really fit in well with the Nintendo cast. He is too realistic IMO. I know that Sakurai said that it takes a lot of work for a third party rep to get in and when a character does that character is a special case, but I think that he made a mistake with snake (no offense to anyone who likes snake).
Lucas
Either he's back with a different moveset than Ness (either could have a new moveset), or he's gone. There is just no reason for him not to be a costume if they are so similar.
Jigglypuff
It would really throw me for a loop if Sakurai actually cut her. I don't think he is ever going to cut a character that has been in 2+ SSB games. Still I think that Jigglypuff could get cut because of better choices from the franchise i.e. Eevee, Mewtwo.
Mario
I mean, I know this guy has a lot of popularity and support, but I just don't see him coming back. I mean honestly. What does he even bring to the table that isn't covered by Super Captain Luigi Time? The color red? Wrong! Luigi has a red alt art. So yah. Therez jus no reas0n. None.
u no
#LUIGI DA BEST #LUIGI NO.1 #MARIO GETS THE AXE #HASHTAGSWAG #EVERY YEAR IS THE YEAR OF LUIGI
Luigi
I mean... I mean u no? Its like y do we efen need Merio reps 4? Luigi is cool in all, but he can't step to the styles of Mr. L so it's like y efen boter? Right?
#MR. L DA BEST #SORRY WALUSERIGI #######
#SECERT WALUIGI IS ACTUALLY DA BEST DON'T TELL N E 1
Mewtwo
I mean BLuetooTH wasn't even in Brawl, but Jigglypuff is just so much more important so yah he desevz 2B cut.
#SNIP SNIP #UR TEARZ TASTE GOOD #
I LIKE TEARS FOR FEARS