They don't contribute to visual style at all. If they do then you should have another discussion about that because your development process is broken.As a developer, I'll disagree. Gameplay, combat, and inventory absolutely contribute to a style. I've had so many long discussions on stuff like this.
We don't know how many of these skyboxes will be out of style in the remaster. From three (I think?) screenshots of ME1 released so far all three have severe styling changes in them, in skyboxes and general lighting.And, yes, it's different, because Tidus is the MAIN CHARACTER and you see his face for the majority of your 100+ adventure. Not a single skybox seen for as shortly as 15 minutes that you leave behind.
No idea where you got these "15 minutes" of yours because chances are that you will be staring at these changes for a much longer time than you'll be able to see the face of Tidus.
Because that's how style works. Face of Tidus isn't a part of it really.