What exactly have you firgured out, that its a MG game, that is obvious. But please tell us more, what game is this exactly? What Snake is that? What is actually going on? You say its not a puzzle so please answer us.
There's nothing there to speculate what kind of game it is, so the intent of the trailer wasnt to throw clues for people to figure out WHAT kind of MGS game is or when does it take place, it was meant to be seen as a new IP and it is way too obvious that it isnt.
In all honesty most of the disappointment comes from the fact that id much rather have a new IP (and heck, id be even more excited if Kojima worked on it) rather than another fucking metal gear game.
Its almost like a joke on itself. A lot of people are waiting for Kojima's next thing and "ZING! fooled you! im trapped on Metal Gear foreverrrrrrrrrrrrrr"