This is definitely at least in-engine, likely actually in-game footage:

• characters swimming in the water during both of the beach shots have no animations whatsoever, they just stand on the water like they're jesus christ.
• one of the container ships in the later overhead shot showing the derelict bridge is entirely untextured and extremely low res, while the rest of the environment is highly detailed
• in the opening shot, parts of the city are billboarded or simple blocks to provide a basic skyline shape, while the areas around the prison are extremely detailed

The NPCs standing on the water also suggests NPCs are driven by the final actor and animation systems, but the animations for swimming or walking through water are just not done yet.

We also see a significant difference between the recreations of florida man memes, where every motion is keyframed to match the original videos, and the parts of the trailer where we see NPCs actually running their regular animation loops, as in the beach, club or road scenes.

Now, will we see this level of quality in game? Yes and no. Usually, a small elite team builds a vertical slice, a single mission in which every little mechanic already works, followed by many larger teams then building the rest of the game, trying to match the quality of the original template.

A good example of this is the original 40min E3 demo of cyberpunk 2077, which exists in the game 1:1 today. This vertical slice was awesome, but later missions usually had fewer alternative solutions, less polished environments and an overall lower interactivity.

So while I'm sure the robbery / prison / parole hearing part is fully fleshed out and will likely be included in the final game as-is, other parts of the game might not reach the same level of realism. Even if you ran the game on the same high-end workstations the developers are using.