My personal opinion is this will be considered normal wear. It is not unique to MS. I've seen similar wrinkling in multiple Lexus and BMW/MBZ with higher bolsters (some mfgrs call them "sports seats") from other owners.
I've learned over the years that I need to lift my rear end up a bit as I get into the seats to reduce wrinkles on the lower and side bolsters. If you pay a lot of attention, I suspect you are moving that leather as you get in and get out, and you will increase the problem if you sort of keep your rear-end seated and pivot as you get in or out -- effectively sitting for a short time on that side bolster which pushes it down to form the curve you see.
Also, if you are not hydrating the leather, it will age less gracefully over time and wrinkles like you are seeing will become exaggerated. Be sure you do a quick wipe down with a clean, damp cloth every time you wash your car. I do that, as well as keep my leather cleaned/conditioned. As gross as it sounds, leather is a natural product just like our skin. It needs a little maintenance and wrinkles will occur where constant movement occurs, but no matter what we do, our faces and skin will age with time -- so will leather seats, especially where movement occurs.
In my personal situation, not having MS automatically move the seat back and forth as I enter and exit the vehicle -- like every other luxury brand has done that I've owned for years -- exacerbates the problem. So, I have set up another profile in my MS called Exit that has the seat way back and steering wheel retracted and fully up; When I park, I try to remember to change to the Exit profile, then use the techniques to keep my rear end off the bolsters I described above; Before I take off, I press my profile and the seat/steering wheel goes back. Having this extra room to get in and out has absolutely helped reduce the amount of stress I'm placing on my side bolsters, so hopefully they age as well as has been the case in my former rides...
Good luck.
