I believe its normal wear n tear. My speedy 30 mono also has that pesky wrinkles on the underside of the handles and the sides too. N yes, when you clean the handles with baby wipes especially, the wrinkles becomes more pronounced. And I also noticed that, some part of the handles do wrinkle more... this is probably due to the way our palms hold the handles... so no worries dear , its normal... But it wd be good to condition the vachetta leather ( esp. the handles) with vachetta leather conditioner , eg , from LMB, that way the leather stays moisturised , just like our skin :) The handles do tend to get dry with age...
I agree with a couple of the others, it looks like the leather got dried out. Seems like the cracks are more pronounced now because it soaked up the conditioner. I'm sure some of it is normal wear/tear but I would think it wouldn't dry out much unless you are using some type of a cleaner on them, or a hand sanitizer with alcohol in it.
The one picture from a distance isn't as noticeable, just in the close ups.
I've seen that before on vintage bags that I've bought. The leather already has little hairline cracks like that, but when you put the conditioner on it gets in the cracks and darkens them. I don't think it's flaw or worthy of a return, it's just leather, and leather gets dry and cracks sometimes. :(