I am using the latest daily build. If I add any annotations, it adds be default the current PC User name.
How to manually change author name?
Adding PC user name for comments is common in many programs and is due to the underlying MuPDF library. so no use suggesting to use that for removal.
There are very few 3rd party editor tools that allow such mods, since I think (I may be wrong) that its a “feature” of adobe definition for identity of commentators.