Amazon itself has had similar issues, products announced but not yet available sometimes have hundreds of "reviews". Unsurprising that they wouldn't worry too much about Metacritic's occasional ridiculousness.
People need to take reviews with a grain of salt. Watch YouTube videos, see what people in the actual community say, try a demo, and then buy the product if you feel it will be a good investment of your time and money. Meta-critic has never been reliable source of reviews in my opinion, and should be ignored totally.
I like metacritic for a quick estimate of how good a game is. It's not going to be right every time (Dark Souls, in my opinion has the best fighting mechanics for any rpg I've played; it's my favorite game), but usually a game that scores 90 will be better than one that scores 80, and so on.
I've noticed that when many games are first released, they are almost always in the 90s on metacritic and then after a few months, if the games are decent, they relax somewhere in the 80s or 70s. I don't see any harm in any ratings included with games.