It always happens with these big releases. The early reviews are overwhelmingly positive, then when more reviews come in the score drops a ton. You can't trust early reviews at all. I don't know if people are paid to rate it highly, but it's usually from people the studio did a favor for by giving them an early screening and they may be compelled to give it a higher score because of that.

dude, a 9.2 before the movie even comes out and you don't smell a giant rat here
The movie has already been seen by literally thousands of people with multiple premiers across the English speaking world, and reaction from those folks has been mostly very, very positive. So for the film to be getting high scores right now is perfectly consistent with critical reaction thus far.
Now, if you are are talking about audience scores in places like the IMDB or Rotten Tomatoes, those are never to be trusted, ever, at any time, for any film or TV show. You don't need to invoke some dumb ass conspiracy theory to reject them.
Any site which allows users to voluntarily enter scores and reviews without making sure there is one score and one review per user, and never has a process in place to police spam reviews from the same user under different accounts, or doesn't verify if they've seen the content, must be shrugged off as a source of utter bullshit. Even one of the former editors of Rotten Tomatoes publicly stated that their audience scores, at that time at least, were nonsense he personally didn't trust.

dude, a 9.2 before the movie even comes out and you don't smell a giant rat here
this happens EVERY TIME a comic book movie comes out
The Fearmakers Blog
https://thefearmakers.blogspot.com/

Can you prove this or do you routinely pull such claims out of your ass?