I'm not sure -- I haven't worked long enough at a company where managers had their own office & everyone was in an open office plan.

My experience was that everyone, including the CEO, was in an open office (40+ person startup, 800+ person growth company). But that it didn't really matter all that much because leadership (senior or not) was barely at their desk anyway.

I do agree that if senior leadership wants an open office plan, they should commit to working in such an environment with their teams.