You might get them as NPCs like Hilda because they can do all sorts of additional customisation to NPCs that we can't access in the character creator.

But short of a major overhaul of the character creator, we're not getting it - and even if they did overhaul it, it'll be about what new options they want to prioritise. Giving the option for hybrid races would mean needing a lot more variations for character designs, and you're probably not going to get any special body models, just faces. (Even Hilda is just a tall Midlander with modified ears.)