From a corporate/team standpoint your note made me remember the advice given by the late Andy Grove in High Output Management.

Andy presented the challenge at Intel as he became the CEO — that many employees wanted to talk with him. He was able to optimize the gap using a general window to attend to these general conversations — like 2PM.

With that I would say that the move to avoid interruption should be coordinated by the receiver, the one that is supposedly in a concentration session. So at the corporate level the team can work out a way to signal these things — book a meeting room etc.