Consider an interview of Yoshida back from 2013: https://www.siliconera.com/2013/02/2...baby-behemoth/

Q38: In terms of new races, what kind of races are you looking into and will mixed races be introduced?

A38: I don’t think we’ll have mixed races for a while. Since it seems like Viera is popular around the world we have been proactively looking into this, but since having a rabbit male might be kind of weird, maybe we’ll look into having a separate race for the male counterpart.

I believe Occam's Razor applies.