Another possible example of this that I thought of yesterday: church worship teams, which frequently lead songs whose theme or refrain is “Here I am singing this song and worshiping”.
Very often (not always) the first type of activity is just your basic grift.
The second type of activity may just be the kind of feedback loop that arises naturally when you enjoy two activities purely for their own sake—and one of them happens to involve some form of disseminating information.
An example of the second would be a podcast and blog about pen & paper products, in which the writers/hosts actually do make heavy use of pen and paper products—but mainly to keep track of podcast episode ideas.
I think there are two subtly different types of activities to be teased apart here.
In the first: you’re nominally an “expert in X” but most of your time/energy goes, not into X, but into telling other people how they can become good at X.
In the second: you do spend a lot of your time/energy doing X, but your need for X is mainly generated by how you disseminate your expertise about X. In other words, if you were to cease regularly talking about X, your actual need for X would be greatly diminished.
Specifically, I’ve been thinking about whether a suitable term exists for this kind of activity.
Been thinking about this for a while too:
For a while I've been thinking about people that tout themselves as experts in X but are really (self-professed) experts in being expert at X.
I'll call these types of people the Meta Experts.
Meta Experts may be too kind a term. In many instances of this kind of activity, there is more bullshit involved than "Meta Experts" would suggest.