This post is kinda long so if you'd like to skip to certain topics, use CTRL + F and search for the topic you're looking for. That said, here's some key words that I have mentioned in the post: Trick Room, Spritzee, Hail, Sun, Rain, Omanyte, Purrloin, Vullaby, Drifloon, Doduo, Offense, Ponyta, Bronzor, Gligar, Meditite, Misdreavus, Porygon, Foongus, Munchlax
From what I've played so far, I've noticed one thing: Trick Room is very strong. When you have a viable setter that is immune to taunt in Spritzee and multiple ways of supporting it into setting Trick Room such as Fake Out, Intimidate, or redirection support (Follow Me and Rage Powder), it's kind of hard to deny this playstyle has a lot of potential. Also, while Spritzee seems like a sitting duck after setting Trick Room, that's really not the case. With Wish and Calm Mind it can establish itself as a threat to other Pokemon that aren't Meditite and Scraggy. Dazzling Gleam as a spread STAB, or Draining Kiss for semi-reliable recovery make its longevity quite high and it's really all it'll need to attack, as the teammate should be ready to take apart any Poison, Steel, or Fire types from the opposing side. Apart from Spritzee's amazing setter capabilities, the playstyle also has tools such as Foongus to spread sleep, Munchlax so make the sun matchup less annoying, among a lot of other Pokemon that can excel in Trick Room.
I believe there's a lot of room for potent and creative strategies in this metagame, as I've seen things like Z-Trick Room Bronzor, Z-Sunny Day Ponyta, among other things that seem to really pull their weight. Hail and Sun seem to be the most prevalent and viable weathers, although I feel like Rain has potential cause Omanyte has that strong Muddy Water and Purrloin having Encore, Thunder Wave and all those disruptive moves really messes up the opponent if not attended quickly. Having to set rain manually is a bit of a pickle, though. As for offensive play styles, I think there's a wide variety of ways to build offense and the only requirements for success that I can think about is that you need to be have a good lead vs Trick Room, ways to get around weather teams, and a check to the Tier 1-1.5 Pokemon, which is not too hard, as they can fall prey to a lot of different things. This can all change as players innovate new strategies however, so if you believe I'm wrong, show me.
There's a few Pokemon that I think could be doing some serious work but I haven't seen anybody pick them up, like Vullaby, Drifloon, and Doduo. I don't have much opinions on them, but their kit seems to be good enough to be viable in some way, so I'll leave that up as discussion points.
And finally, a little bit of information about the Tier 1 Pokemon that I think is worth mentioning to give everyone a heads up on what they can do, and what they're weak points and limitations are.
Gligar has an amazing STAB combination, great 19 Speed, very good bulk even without Eviolite, Swords Dance as a setup move, and good Attack, but I personally find it to be slightly underwhelming considering its movepool, stats, typing, and ability are so good. It needs to trigger Berry Juice in order to use Acrobatics, and in a Doubles environment, you can easily be double targeted and never get to trigger the juice. Earthquake is surprisingly weak because of the 25% damage reduction that spread moves receive in Doubles.
236 Atk Gligar Earthquake vs. 0 HP / 156 Def Ponyta: 18-24 (85.7 - 114.2%) -- 6.3% chance to OHKO
236 Atk Gligar Earthquake vs. 36 HP / 236 Def Grimer-Alola: 18-24 (72 - 96%) -- guaranteed 2HKO
+2 236 Atk Gligar Earthquake vs. 36 HP / 236 Def Eviolite Grimer-Alola: 24-30 (96 - 120%) -- 68.8% chance to OHKO
Long story short, Gligar will simply trigger the Berry Juice of a full health Ponyta (with 21/14 bulk) and fail to OHKO a Pokemon with a Super-Effective +2 Earthquake if it has 25/14 bulk with Eviolite. However, at least Gligar has a pretty immense movepool with Taunt, Tailwind, Knock off, Rock Slide, U-turn and probably a million other things to make itself a very diverse Pokemon both as utility and offensive presence. I've also seen some Groundium Z sets bouncing around that sort of help Gligar's issues with Earthquake, so that's neat. it also dies to random ice moves and lots of scarfers
Meditite is funny. It's probably the best Fake Out utility in the meta, it has reasonable bulk (21/12/12 with Eviolite), semi-reliable recovery in Drain Punch, great coverage, and its strong af. However... it's 16 speed as a fighting type makes it prey to Flying types, and Misdreavus. Fairy types like Spritzee, Cutiefly and especially Snubbull can also find it in themselves to give Meditite a rough time. I feel Meditite shines when supported via speed control, so it can make use of its coverage and sheer power.
Misdreavus is the premiere Ghost-type and is boasting a nice 19 Speed at max, a great Special Attack stat, respectable bulk, perfect coverage with Shadow Ball and Dazzling Gleam, having a setup move in Nasty Plot, and a plethora of support moves such as Taunt, Will-O-Wisp, Icy Wind, and perhaps even Z-Destiny Bond. But being a Ghost-Type is a very hard life, being weak to Knock Off, Sucker Punch, while being unable to break through Pokemon like Grimer-a, Porygon, Foongus and Pawniard. It also loses to Carvanha.
Porygon has incredible bulk, nice coverage, decent speed, lots of power, and two different sets that are played very differently (Trick Room and Z-Conversion), and even then, it still has other support options like Icy Wind and Electroweb, so it's a very good mon. Sadly, Porygon has a few flaws that include being completely obliterated by Meditite and to a lesser extent, Scraggy, having difficulty vs opposing speed control, and having to set up to show its threatening presence. Let's also keep in mind that part of Porygon's offensive prowess comes from the Download ability, which you can counterplay with something as simple as your EVs. That aside, it's still a powerful presence that needs to be accounted when building a team.
I await further discussion on all this and much more!