I generally agree with what you say there. I had forgotten about trust levels coloring user names, and was essentially suggesting the second half of this:
So for those community members that get curious about what happened to Bill, they can start a meta topic about it, or click on his user page to see the same public ban information (a brief sentence, plus duration) Bill himself can.
That seems particularly important since without it, it may even be hard to know if Bill’s absence is worth asking about. If the info on the user page is already implemented, it’s not somewhere I found noticeable; even PM still seems to work on people I assume can’t get them.
