I am smelling more vagueness because, Writers Stack Exchange community are willing to change their site name from 'Writers' to 'Writing'. They already claims this:
We're about the product and the processes to get there, not personal identity. We want novels, poets, and essayists, and we also want scientists (who write papers), marketers (who write, e.g., brochures), software developers (who write technical documents), etc too. By and large we aren't getting those people.
Therefore, if 'Technical Communication' is to be serving purpose of 'Technical Documentation' or even the part of it, then it might conflict with this site.
Therefore, as I mentioned here as well, it is high time that a concrete, clear and concise scope of this site is clarified before it adds more confusions and hassles.