None of the stuff I've seen of Kalos looks ban-worthy. Water form seems really easy to deal with (I do notice that which side is "high" is random, not legality important but interesting). The fire pillars on the fire form do almost no damage and knockback as do the hits from the swords on steel. Those hazards are just geography to navigate and not actually threats to combatants. I'm not entirely sure of the power of the super predictable attacking pillars on dragon, but my early read was "weak". Unless there's a champion's room we haven't seen that is problematic or unless the stage features we've only heard about but somehow haven't seen in action yet (the metal pool and Rayquaza) enter the picture in a bad way, this stage seems like an easy legal stage.
Garden of Hope's crab is confirmed to do 20% damage and almost no knockback:
https://www.youtube.com/watch?v=mjYGNGMz-kI
I think Garden of Hope actually has a lot more merit than it seemed to have at first. It's a bit big, but otherwise it has pretty tame geography and really doesn't do anything of concern.
Duck Hunt is just obviously legal in the same sense Smashville is obviously legal. We've seen perfects do nothing, failing to win a round does nothing, and all around the stage is just flat ground with platforms on either side corresponding to the shrubbery, a player controlled minor platform (the dog picking up the ducks), and the grass hiding mechanic which doesn't seem very significant but may be situationally interesting.
I really like Orbital Gate Assault. There is actually always a lot of ground; it just shifts a lot. It's clearly a stage built for aerial characters, but it doesn't seem any more severe in that direction than FD is for the ground characters. The hazards, insofar as they even exist, seem utterly trivial to the point we really could treat them as not existing. I'm not sure you can easily draw a direct comparison to previous traveling stages either since every form on this stage apperas to be horizontal whereas stages like Rainbow Cruise and Poke Floats both had sections with way less ground than any section of this and had far more vertical gameplay.
The one stage you guys are buzzing about that I'm really not feeling is Woolly World. It's a walk-off for half of the time, a "no ground but lots of easily camped platforms" stage for the other half, and completely huge for all of the time. Like, I bet in the strictest sense of the word this is a fair stage and as a very stage liberal person wouldn't be upset to go to a tournament with a stage like it on, but it's probably overall less balanced than a conventional walk-off so, I kinda feel like unless we discover in play some surprising gameplay dynamics here that seem unlikely, this stage isn't terribly defensible unless we also want to make Mario Galaxy, Coliseum, and Wii Fit Studio legal as well which we probably don't want to do. I think we're better off focusing on our plethora of excellent other options.
We are really just swimming in legal stages; the info we're seeing is just making more and more stages look good as opposed to what happened with 3ds wherein a lot of stages looked promising but as we learned about them it was clear they had significant design flaws. We're looking at a future with most of the stages legal, and we won't even have to get into conservative vs liberal stagelists to do it since most of these stages are just really reasonable in the first place. Procedure will be a challenge (starter vs counterpick is just an awful, awful way to do things still; I cringe everytime I see anyone suggest a particular stage looks like a "counterpick"), but I think we can make this work and end up with stage rules in this game that actually make almost everyone happy.