I don't know about anyone else, but the point I'M trying to make is not "Snake is DEFINITELY back", because my uncle doesn't work for Nintendo.
The point I'm trying to make is that there is literally no concrete reason to believe he WON'T be back, and trying to say otherwise makes no sense. There is reason to believe he might be back though, main reason being that Sakurai said no plans for cuts were in the cards, and the only character he said there was difficulty re-implementing is Ice Climbers.
As for Pac-Man, I disagree with his inclusion not because of an over saturation of third parties or anything, but because I think he is undeserving. If he does get in, I will be happy for those who wanted him. However, he's just not that relevant or iconic, not on the level of Mario, Sonic, or Mega Man anyway. If I had to have a Namco rep, it'd be Jin Kazama or Kazuya Mishima from Tekken. They are way more iconic than Pac-Man, and have had much more staying power, and overall, I feel Tekken has had a way bigger influence on the gaming industry than Pac Man has, even if the original Pac Man was revolutionary (though this is a moot point, as the industry was hardly existant at the time). Tekken also has connotations with Nintendo due to Tekken Tag Tournament Wii U, which includes bonus costumes for every character on the roster based on various Nintendo characters (they EVEN have Captain Falcon). There is also a Mushroom Battle mode, where various power-ups from the Mario franchise are utilised mid fight.