Taking away Team Preview

If they took away team preview, every team would either have a Zoroark, or 6 Zoroark counters. And I don't think I'd like it if the meta was focused solely on Zoroark.

 

That specific line. Man, since Toxi's got a x4 weakness to Psychic, it'd be highly likely that it'll get hit by one, but Zoroark's immune to Psychic. That gives you literally two free turns. Talk about strategy!

 

If that happened I reckon Volt-Switch Custap forretress would soar thanks to the buff of sturdy and volt-switch can give momentum. Then if there's a set-up sweeper, custap explosion can stop it in its tracks. Whilst I may have stealth rocks on this thing it will mainly function as a bomb, coming quickly to kill everything. Also, partial weather teams will get a massive boost as they are so unexpected that you're going to have to have a Tyranitar or Charizard Y Everywhere

 

Scouts and Pivots would definitely become more prevalent. I imagine Voltturners such as LandoT and RotomW would become MORE prevalent than they already are, as well as things like Flygon, Mienshao, TornT getting more usage.

I also imagine some teams having more than 1 Pokémon that equips a megastone despite the "1 megaevo per battle rule" just to be prepared for more situations and could also create more mindgames due to the lack of team preview.

 

One thing that would surely return, in some form or another, is the GyaraVire. It'll be easier to pull of without the team preview. Other similar combos would most likely happen too. Also usage of Outrage would be discouraged, at least until you have seen all of the opponent's pokemons and gotten rid of all the potential Fairy types.

 

I actually like that team preview is a thing because it makes for a more strategic playstyle imo. Plus, it stresses team and set building a lot more because it makes builders be more creative with their sets due to the fact that they know their opponent can see mons at the beginning.

It seems like removing team preview only really ends up hurting the game as a whole imo, as I like that surprises come from creative sets and not whole mons. Also, when you look at tiers like Ubers and OU, introducing lower level mons can change up whole playstyles on preview. It's part of the reason why dugtrio became popular in Ubers for a while when everyone was spamming klefki + pdon, because it forced klefki users to become a little more hesitant with bringing them in on the chance that their opponent predicts them and traps them.

TLDR team preview actually improved the metagame from what I can see.

As far as what would change, the emphasis again will change from team building around set innovation to surprise mons and pivot mons, like you all said, and cutting back on hyper offense and set-up mons. Basically, it would switch the importance back to defensive and stall mons, which I'm personally not a fan of

 

I agree with @[member="Filibuster"].

Any game that are strategic (Yes, competitive battling is strategic) should allow you to come up with ideas to fight your opponent. It's not as if you can change your team anyway.

It'd be neat for GF to come out with a Blind Pick game, though.
But lets face it, Pokémon needs a stronger competitive base before that ever comes.