I'll also add that it's a class signifier, as much as we're all loath to admit it. The upper-middle and professional classes really don't like direct communication and they have control over key parts of most companies.
This is a great post: I never saw it expressed so clearly.
I am the type of person that loathes office politics, and I am quick to point out when a decision is politically driven to satisfy someone far above us.
Another way to look at indirect comms with senior staff: Behind closed doors they are frequently direct with other senior people. (I had some years in my career where I attended closed door meetings with people more senior than me.) In "public" (speaking with the peons, two levels or lower than them), they appear ultra-indirect, always using company talking points. It is grating and inauthentic to me, but I can assure you that many of them are hiding their true comms style to get rich as a senior manager.
What you say about senior people/leadership is pretty accurate, although I'm not sure that the directness is their 'true' comms style. My experience with people at that level is that it's really hard to tell what their true communication style is and they may not have one because they've spent their whole life switching their style to fit the room.
I'd say the difference between a lower-class direct communication style and an upper-class one is that the upper-class can speak indirectly, they choose not to. Whereas the lower-class is gatekept out of such things absent some other influence (institutions, formerly well off family members, etc.) So the professional class uses the register to determine the difference between the guy who's wearing jeans because he grew up in hick country and doesn't own any 'nice' clothes and the guy who's wearing jeans because he's so important he doesn't need to follow the rules.
This is also why there's a lot of friction between the professional classes and engineering. Engineering has status and yet a great deal of them are intractable and refuse to adapt, which reads as "you're beneath me because the rules apply to you but not to me". (Of course the engineers are just like 'the rules are stupid and arbitrary' because class distinctions don't matter a ton to them/us in comparison. Like if there were rules about what language to use depending on your height compared to the other person's. Who cares?) I'd say this happened because techies developed a culture of their own before being subsumed into the dominant socio-economic apparatus.
There are some other differences between lower-class and upper-class direct speech, mostly in diction. I'm very good at code-switching and one of my favorite things to do is find a group of good professional progressives and then call their diversity bluff by deliberately switching from a professional register to a working-class/poor one and watch them try to deal with the cognitive dissonance. It's great fun.
It's also something to watch because as you've noted, those in high places speak differently depending on their opinion of you. It's a good way to figure out what they think of you and it can be really interesting to see what flips them from "this person is a peon/useful for their interchangable ability(abilities) I need at this point" to "this person is unique enough/has enough connections/etc. to be worth cultivating in the future."
