I know we can't report leaks, but there is no way this "leaked" trailer is real. I do not think it's real, so I don't think it's a leak. GTA Forums seem pretty confident it is a fake because they mention clips from other games in it. So I feel confident posting this. If it was real, Rockstar would have had it scrubbed already too. It is linked to this person's Twitter account.
Twitter
No way that is real. The voices are ai, meaningless script, thevery first shot is from the MS Flight Simulator trailer, etc. There are Watch Dogs clips as well as The Crew in it. It mixes some super high fidelity shots with some that are not. It makes no sense. But they do have a good grasp on how Rockstar likes to make stuff in terms of music and shots.
I doubt the first trailer will even have talking.