Captain Falcon and Ness share a special connection with Smash Bros. Even if they never get any new games, they will live on in Smash Bros, they're just Smash Bros family! As for new games, F-Zero could still be around even with Mario Kart being a thing. I imagine it appeals to more "hardcore" players with its music, designs, no item usage, and such. They're very different and it wouldn't be so bad to see it come back from a business standpoint or otherwise.
As for the Shulk thing! It
IS very interesting that his anniversary is June 10th! I imagined him as a secret character, but what I imagine more now is them showing a trailer for his new game "X" and then later we get a trailer in Smash Bros featuring the one and only! But I also expect to see Pac-Man, Miis (maybe) , and a fourth person like Palutena just to keep it an even number. Maybe just Shulk and Pac-Man?
As for Pac-Man... I saw a video of his new game just to get an idea of what he's like and gosh, he seems like... they make it so you kinda wanna accept him as a man, but he has a little kid voice?? I don't quite get it. Hope they go with this Pac-Man instead, though they probably wont since that doesnt make sense for marketing: