Why would someone render a derivative figure unable to utilize textures and content related with another companies proprietary asset? Especially if said derivative was created by a contracted artist who creates assets for said original product of competing software? Especially if it's just a one off cash grab project that in no way threatens the bottom line of said company and in light of a certain bridge software being rendered unusable by changes and a certain vocal demand amongst a certain community? 

Beats me.

How such a thing could slip through QA unnoticed is beyond me. Especially considering how certain features of the asset in question are undeniably broken?

Who knows?

Oddly enough figure is no longer available at Rendo. Shrug, quite a mystery.

In any case draw your own conclusions, it's merely opinion and speculation on my part.

I won't bother providing any elaborate illustrations, I've already voiced my opinion, and trust me when I say I've probably looked more deeply at the figure than maybe anybody... there's more extreme comparison to provide but... delete some edge loops, a bit of sculpting and scaling, some topology changes, move some shells around and some new cuts/unwrap passes, change from Udim to stacked, might produce something similar.

Anyway. Only because the question was forced, draw your own conclusions.