I'm gonna be totally honest by saying that I don't really know what that mean, but wouldn't it be possible to release such content as a "bonus" of some sort? As
@flashn00b said, you could probably just have him grunting and screaming and that would be fine. Hell, if I understood you correctly, the main problem is that the old Thorne model wasn't on-par with what we currently have... is it due to customization? If so, I would only speak for myself, but I personally wouldn't care all that much. A half-eaten mutant is enough of a cool concept to add some wacky items to anyway.
Also
@DudeBY , the think is probably not only that the sales were disappointing but that they were considering the amount of work it requires to create a character. Besides the voice acting, you also have to create whole new models, a few customization items... And make sure the model looks good with the universal items and animations. It definitely can be time and resource-consuming.