Hope your right and the green Rau sees the light of day.
Your have a point with the fact that Yamato has to use the molds, but a TV Q-Rau has a few differences (bulkier legs, antaena, eye piece, other panel lines and engravings). I doubt Yamato would only repaint the existing toy since they pay a lot of attention to the lineart and accuracy.
We can still hope!