I wouldn't recommend doing this on purpose, but if you say something that forces the whole room to stop and consider, you can often break the conversational flow and leave a meeting of managers dead in the water.
You can also do something that wipes an individual manager's mental cache and they'll spend days trying to remember what everyone is up to and what's happening.
I think your final sentence is close, but I'd rephrase it: for managers, those disruptions and conversations in your schedule are them dealing with things that require intense concentration. I think most of them understand what disruption feels like, they just don't associate sitting at the computer typing with that focus because it's not the mechanics of their role -- their focus manifests differently.
My managers only rudely interrupt me when they, themselves, are clearly still processing something their boss said to them and they need my input to unblock that process. Or some kind of thing I need to do now, again to unblock whatever they have going on.
> You wouldn't see this being a problem in careers like HR/Management/Sales. Because an individual can still be somehow productive without being in the zone.
I think it could actually be the other way around. That kind of work is very conductive to be "in the zone". In my few attempts at managing groups of people, I've learned that the work that's easiest to give you the state of flow is one where "next actions" are always obvious, and you get rapid feedback. Work where you can - and often should - substitute moving forward for thinking things through. Work where thinking gets distributed, outsourced to group interaction. That is sales and management, and I imagine lots of HR also.
So in a way, I think "people people" are "in the zone" much more often than we are, which is why they may not understand just how hard it is to get there when your tasks are brick walls requiring intense concentration.