Aside from whether the term "GTA V engine" is meaningful when that game came out 10 years ago and has had plenty of ports and engine upgrades since...

The lighting model and materials are meaningfully different in multiple ways. This footage is in a separate class from GTA 5. Look at https://youtu.be/QdBZY2fkU-0?t=21 for example, just off the top of my head glancing at it:

* The beach sand is highly detailed both from a texturing perspective (you can see tracks and footprints everywhere) and from a geometric perspective. This kind of terrain detail isn't a thing in GTA5, they use much coarser terrain so there's probably new tech being applied there. The way shadows interact with this terrain is much more realistic than GTA5-era tech, you can see the shifts in elevation deform the character shadows.

* The material and lighting model for skin/hair is vastly improved over 5. If you look at the three women in the left foreground you can see each of them have meaningfully different hair texture and skin appearance, with subsurface scattering evident for the skin along with a good combination of both realistic specular and diffuse light. If you pull up a screenshot of Franklin from GTA 5, his hair and skin rendering is simply on a different level from this, and he's a main character so he got plenty of art attention.

* The level of detail here exceeds that of comparable scenes in GTA5. Higher numbers of characters animating and interacting with the environment, and lots of environment detail. Of course regular day-to-day gameplay won't necessarily be like this - there are good design reasons why it shouldn't be, and this is a cinematic - but this is stuff that engine didn't really do. Crowds of this nature are historically a real technical achievement and you really only see them in games like Hitman or GTA as a result of a lot of engineering and tech art work.

* The water is far more detailed than anything GTA5's water model is capable of, both in terms of rendering fidelity (especially reflections) and geometric detail. The people standing in the water both cast shadows on the water and have reflections in the water. (These look like they're probably screen-space reflections... IIRC GTA5 primarily relies on skybox reflections, which wouldn't achieve this. They might be combining both, or pairing one of the two with ray-tracing.)

* The draw distance is extreme. You can see a lot of fine detail in the far distance, and it wouldn't be legible like that in GTA5 even with the settings cranked up.

* The atmospheric/lens stuff at work here is good too. You have a haze on the far detail combined with a very good looking depth of field blur and motion blur for fast moving objects like the helicopter. Some of the lower hanging clouds look like they're actually passing in front of the buildings.

* Some sort of high fidelity global illumination model, or a good approximation of it, appears to be at work here. You can see it on the underside of the umbrellas and their poles, where the umbrella itself is gently occluding ambient/sun light from the underside and the pole, without casting 'hard' shadows like the characters do. I don't see the kind of artifacts normally associated with traditional screen-space ambient occlusion (SSAO) techniques in this footage, and GTA 5 relied heavily on SSAO with a fairly ugly implementation. If they're still using SSAO it's vastly improved here.