Definitely not surprised that it's like that due to it being a Kojima game. Im definitely expecting some crazy plot twists in this one.
Make sure you read your emails. There is A LOT of story and lore in those emails. Like big things that should've deserved a cinematic (for example, the reason why Troy Baker wears that gold mask). There's a lot of really fascinating stuff there, especially with the new content.
It's kinda similar to how you were absolutely required to listen to all those codecs in MGSV to get the whole story even though it seemed completely optional to the player.