It's true however it shows that the assets, details and lighting exist. Doesn't mean it'll get optimized to run looking like that at 60fps...but it's nice to know those assets are there. Especially knowing that hardware will evolve and these games will upgrade forward.There's some semantics at play here. The trailer didn't show actual gameplay. Yes, it was made using the in-game engine, but that's different from saying it was literally how the game appears like as you play it.
It's akin to showing a Gears of War cinematic and saying it's "in-game."