> So your theory is ...

No. That's clearly your framing - don't draw me into your strawman.

> but I think a more plausible explanation is that

Or, that a majority people in the USofA that are described as black in the USofA have embraced that term, own it, and have used Black Twitter etc. while those adjacent to them ( the "progressives" ? ) use that term as for the most part the "black people" are comfortable with and haven't told them to bugger off and stop using it.

As happened with "ginger" and "nagger".