Eh, no one's entitled to have reviews before a game launches. No one's forcing people to buy something day 1, if they want to make an informed choice they can wait for information to exist. Personally, I bought the game a day before release and by then it was already known that it wasn't a good port. I was informed, and I didn't care.
No one is forcing people but sometimes there are bonuses that you can only get if you buy on day one or pre-order. It's usually nothing too substantial but gamers don't want to miss out on content, even if they don't ever use it.
I suppose so, but Bloodstained didn't have any pre-order bonuses, at least not in-game.