If they redo the YF-19, I'd actually like it to be redone. Completely new sculpt and design. Of course, it'd be hard for Yamato to justify such expenditure on redoing something relatively recent and may not have many re-buyers, so it would make most sense for them to release it later down the road. Considering that they seem to have broken into the Macross 7 properties, it would make sense to them (and us) to capitalize on that for now.
That said, I do want a new YF-19, but I want other M7 valks more.