Edit/clarify : Ok maybe I worded it a little wrong, i'm not asking about the how as I understand what NDAs, and press embargos are, I guess my question is more of a why? Why would capcom even have a release date if they are just going to allow the game and all its content/spoilers released on the internet 2 days prior. Like it kind a ruins the whole release if everyone (that's wants to know can) knows about the entire game before its even officially out. Like I just got a pseudo-spoiler because I channel I follow is posting their LPs and the title description spoiled a bit of the game.

I understand that people still buy game to personally play and experience it themselves, so watching a lets play its not exactly the same but still, imo this is like if Disney allowed the entire plot/synopsis of the next Avengers film to be published on someone's website 2 days before the films release. Like there's a difference between hype like the maiden and castle demo and releasing the entire game before its official.

Original:

My question is concerned with RE 8 specifically, but can be about all/most game releases. How are reviewers and lets players able to release FULL gameplay/walkthrough footage BEFORE the games release, how is this allowed/legal? I understand they provide reviewers with an early access game to do press and PR for, but how it is that channels are uploading the ENTIRE game before the games release. Again not talking review footage but like full on the entire gameplay footage and everything has already been uploaded in it entirety, and these are from official channels and yet haven't been taken down so I can only assumed Capcom is cool with it. How? or Why? I noticed it started yesterday, and im not talking small channels im talking big multi million sub official gaming/lets play channels. How is this allowed? I thought they were only allowed to release once the game officially comes out.