Yes, but Rex would look completely different with his helmet ON depending on realistic or animated, so I don't follow? The entire character looks different between the styles, not just his face.
The significance of the teaser, if that is the actual Rex figure teased ( it must be as otherwise that is an occurrence without precedent), is that Hot Toys have taken the realistic option, therefore any other character in the range would also be realistic.
It would be an unprecedented approach by hot toys to make a figure line where one character is done in a realistic style, then the next one an animated style. Unlikely. Logically and commercially, they would choose one style or another for the whole line else it would be inconsistent and jarring to put them next to each other, alienating collectors.
Imagine an animated anakin next to a realistic Obi Wan......it would look bizarre.
So, if the clones are done like movie versions, the other characters will ultimately be made to look like real people rather than cartoon characters for the figure line to look consistent.