So if you for instance prefer the way your character stands with the restoration staff, so you apply that stance regardless of wich staff you currently are using. Would be pretty cool?
I would personally like this but I doubt it will happen due to visual clarity concerns. I don't know how much zos cares but most games that offer pvp limit visual/aesthetic changes to a point to make things readable/understandable in high action scenarios. The position of staves for a decade has been tied to what weapon type you are using so that could impact things pvp wise in an unintended way. Though you could also argue they could just disable it like they do mementos and some things in pvp.
Regardless, I'd like it personally but I also think there are some concerns they'd have to address first.