If the silhouette doesn't meaningfully change, it doesn't present much of an issue. Only if parts of the mesh start exceeding the original bounds. There's not much of an issue with subdividing what is already there and interpolating between the extremities. Then again, I'm fine with admitting it's going to be a wait and see for now, since the only example we've had so far is the face, which is proven to be higher density in the preview.
You mention the texture and kind of interchange the term materials but I feel like the materials altogether will be the biggest gain. Having more of a distinction between types of materials, to me, is going to effect far more change than higher-res textures (which are still good, of course)
Metallics. A big hubhub was made about making metallics truly metallic, and that's exactly the domain of PBR rendering. Well, one part of it, at least. The alternative is a specular workflow, which is basically what we seem to have right now. Golds such as have been previewed are basically the PBR trademark. Sidenote: PBR doesn't mean single-player AAA PC-meltdowns. It's fairly common nowadays.
It is, but it also has different consequences for the game than higher albedo and normal texture fidelity. Leaves, foliage, small elements like chains and tassels and what have you that are too minor to be worth representing with an actual mesh. You're free to not count it, but I'm also not playing a goal scoring game; I'm trying to explain the breadth of its influence.
It's not just colors, it's everything about presentation. Of course, more vivid colors are good, but lighting alterations can change literally every bit of how the ingame world is presented. The ground, the characters, the buildings, the standalone assets. It's so much more far-reaching than something reshade could ever hope to do. Assuming here that they do a good job of it, of course.
Hardly. It's a very important ambience thing. It works well to sell atmosphere, the distance of objects and more. Reshade, again, cannot achieve the same thing. It can fake it, sure. But reshade just cannot accomplish anything on the same level for the mere fact that it injects at the tail-end of the process. If you've ever used distance fog in reshade, you probably know that its "artificial" (as in, it attempts to calculate and put a filter over things) nature leaves it rather flawed in the sense that it cannot meaningfully distinguish depth other than by a rough approximation, nor can it cut it off where it isn't wanted. That said, you're free to not be impressed by it, but I think it can have a great impact on the feel of a world.
You're right. I'm not sure exactly how they've gone about it, but I'm tempted to believe you. Again, not sure how far they'll go with the graphical update, but even if it's all manual, having more clutter does give the world a more lived in feel. I quite liked the Thavnair preview picture.
I do think you're underestimating how much of an influence this has, but yeah, "better shadow resolution" does tend to be a rather more dry thing to announce compared to "THE GOLDS ARE ACTUALLY GOLD, EYES WILL ACTUALLY LOOK LIKE THEY SHOULD, TEXTURES WILL BE FAR HIGHER RESOLUTION." All bits help, though.
Eh, their changes alone indicate that they're having to dig deeper than just tack onto existing stuff, so I have fair hopes. I don't think they'll rip anything straight from XVI, of course, being that it's a wholly different game, but I find it hard to believe that they will refrain from taking some of the things they've learned to XIV. On the technical side, of course.
It's hard to say. A lot of foundational things are hard to alter, but I don't think hard = impossible. Then again, it's a risk-reward type of situation, I'm sure. Back on the topic of the graphical update, and I know it's ironic of me to say this right after making separate arguments for every little thing, but I think the real deal is seeing everything working in tandem. It's easy to dismiss better textures, or better materials, or better lighting in a vacuum, but seeing everything together is probably a lot more impressive. As an aside: they have neglected to mention it thus far, but I really, really hope they're also adding better AA options. The ones we have and have had for so long were actually terrible even for when they were introduced.
(Sorry if breaking your post up in such a fashion is jarring. I felt it was more lucrative to do it in a piecemeal fashion to avoid anything getting lost.)