It's an aggro focused launch. If it gets too crazy there will be balance changes but either way, control will come up with optimal decks to compete and the race to figure out the meta will be on.
Your reply would be 100% true in such threads at the launch of any expansion we have seen before, but it's not the same, as FortyDust said. That's the most concerning thing, when unrefined and suboptimally piloted combo decks are as good as aggro decks on day 1, it may lead to even worse meta when combo decks became more refined and people will get better at piloting them. I'm not saying it's unfixable and I'm quitting, but it's concerning. Luckily, we still have Classic, Arena and BGs. As to balance changes, looks like they may need a lot of them and it's unclear if they will be able to do it fast with all that mess at Blizzard.
I would like to quote the most upvoted post from HS subreddit today:
They did it. The mad lads did it. They turned hearthstone into a single player game.
To be fair I am not calling for a nerf or saying the design was bad or anything like that. I'm not trying to shit on the expansion. You can do it all you want.
I'm making the observation that out of the 10 classes on ladder I've been playing against, 7 of them play complete solitaire decks. Mage quest, warlock quest. Druid can have up to 5 copies of battlecry 8 attack minions. Demon hunter is doing quest illgynoth otk, hunter and shaman is just doing normal spell/weapon burn, and these are two classes that could easily go non-minion if they wanted to. Also the cherry on top, rogue has a t6 otk garrote deck with iceblock