Yeah I emailed Prime 1 asking what materials they plan to use for the skirt and they said "synthetic leather". I did ask them to consider polystone sculpt (like the 1/4 JH) for longevity as this will be a flagship statue (and fans would be talking about this statue for years and decades to come) so would make sense to use polystone instead. They will on pass my suggestions to the development team. I think if more people email them about this and provide their reasons for the change, they will consider changing it to polystone.
I don't think they can change the front (it'll be difficult to do the ripped effect/battle worn detail using polystone, unless they flatten it and mold it into the legs, but it won't look as hyper real).
Imo they can at least change the back part of the skirt and polystone finish is close enough to the real thing (plus rear area is not viewed or seen as much when displayed, so the change won't be noticeable).
The front ripple synthetic leather is not hard to replace in future, just buy some materials, cut it in pieces and glue. But the back would be much more difficult to repair if and when the material starts fading.
I'm not sure if baby oil will extend the lifespan of synthetic leather. I've done some Googling, some have had no deterioration for 10 years and counting. Others fade and rip in 5 years or so. It's pretty hit and miss, but what is certain is it will definitely deteriorate over time, the question is how long?