Beside butts-in-the seat visibility, the other main achievement of open office - the high density - coupled with opaque walls would make for claustrophobic work stations (think voting booths) while transparent walls would allow to increase the density even more. Historically such density increases have been taking a decade or two. Thanks to corona we're going to jump straight into it.

Transparent dividers have the benefit of showing just how much they are working, as the saliva, mucus, and food particles accumulate.