These are my opinions.
: Hard to judge but I think since desyncing isn't as easy to do as in Brawl (it's been shown that it is possible), they will be placed low for a while until someone manages to make desyncing work in a competitive environment.
: Massively improved from Brawl. Down B being so many times faster allows for more creative combos and control of neutral depending on the Pokemon and all of them have situations where they excel at. Probably high tier, though I can see some counter-play.
: He's been called top tier for quite a bit by a lot of players. I think if he truly ends up top tier, I don't think he'll stay in it for long. Will probably still end up in the higher section of the tiers.
: I think this guy is a sleeper character. His air mobility is amazing and due to the general lack of lag in aerials in this game, his combo game will probably be better then others. High tier at least.
: Nerfed from Brawl but I wouldn't count him out. C4 is too much of a threat once stuck and will basically give Snake complete control of the neutral at that point. I also think he'll be one of the deadliest characters in the ledge due to being unable to be passed through shield, making his tech chase throws more deadly or giving him a free C4 stick. I think he'll be high tier, but among the lower section of it.
: I think they'll be high tier due to their decent mobility and ink neutral. Due to the ink, everyone will have to play A LOT more defensively in a game that is based on aggression. I think other zoners can reliably counter play them, though (Link, Mewtwo, etc).
: Basically will be on the same level as Peach which is said to be high at the moment.
: Has some good things about him (being a pretty fast heavy is a good trait to have, good edge-guarding and a Down B that can switch the momentum instantly in his favor if it connects) but I think he'll be in the mid tier section. Combo food for a lot of the cast due to having the largest frame in the game and his recovery is very easy to edge-guard.
: Either lower end of high or highest end of mid tier. Anti-zoners by design and can do their job effectively and will be nightmares for lower mobility characters, but fast characters can make mincemeat of them due to them being pretty slow themselves.
: Easily would be one of the best characters in the game were it not for his recovery but even then he is still one of the scariest characters to challenge in neutral due to how safe his pressure is (his aerials are all safe and from what I hear is Up Aerial is bonkers). Up B is a good OoS option, especially after a parry, with a free 22%, has really damaging combos and seems to have ways to confirm them into his kill moves. I think he'll be among the high tiers and if patches buff his horizontal recovery, consider him an easy top tier.
: Will be the same as Samus and I think they will be in the mid tier section. Buffed missiles help her in the camping section, Charge Shot now being air chargeable gives her a more threatening neutral and edge-guard game and now has a kill throw + a faster grab. Problems are that she has lost some of her combo set ups, particularly with Dash Attack which makes racking up damage harder in theory.
: Can see really high in the beginning, but I think will drop throughout the metagame. He definitely has some really good stuff (a counter for a heavy is pretty good, Neutral B is a solid projectile that can be comboed into, decent mobility for a heavyweight) but I think he'll see some decrease once people play enough against him to develop counter-play, particularly in exploiting his super amor.
: Tricky to judge but will probably end around the same as Village though I think a little higher.
: Same lane as Ryu. Slightly weaker then Ryu but having mobility in this game is much appreciative. Both will be high tier, maybe top tier (especially in Ryu's case due to how bonkers his damage seems to be).
: Low tier, if not bottom. Terrible recovery, worst mobility in the game, seems to have pretty bad range, absolutely no way to deal with edge-guarding and due to bad range, doesn't seem to have any good neutral options either. He's probably looking as the single worst character in the game right now.