No. The key word here is "dynamic system" what you see in most games including X is referred to as "weather pattern" and "baked lighting solution". The difference here is that the dynamic system is heavy in the resources, it requires its own calculations to measure objects and distance. The light effect is not part of the art / textures, it is a standalone thing. You can see the sun gradually moving while the lighting of the world changing in real time.
So is the weather system. It is not a pattern. A dynamic weather system means the rain dynamically and gradually changing from heavy to soft, while interacting real-time with the other world elements like the wind direction, the look of the textures and so on. Final Fantasy XV Is a clear example to understand those systems better.
The backed lighting system like in X is much less ambitious but it is also not demanding. The day and night "cycle" is 3 different kinds of "world paint" day paint, dusk paint and night paint. The shift between the three happens without any interaction with the world elements, and it doesn't happen gradually, the time of day remains static untill the change happens.
You clearly never played xenoblade chronicles, because it has a full day/night cycle. light slowly fades when night approaches and the opposite during dawn.
this whole "dynamic weather" argument seems like its trying to make ff 15 look way better than it is. it's just digital weather and I doubt the final results will have noticeable differences.
What part of "constantly changing" you didn't understand ? In dynamic system you can see the source of light moving during the whole time, the clouds could block the sun rays during the day. in the other method, the "light" is static until it is time for dawn, that's when the world paint "slowly" changes to orange, then it stays for a few minutes, then it will "slowly" changes to a night sky and will stay exactly the same until the next morning
I'm just talking facts, the quality of XV speaks for itself.
Skip to around 27:30 to understand .. Hopefully
ٍSkip to around 4:20 too see how the dynamic lighting affects the shadows:
