Very odd. Grading each student submission, identity is concealed with "Participant #" instead of name.
But on the "View all submissions" page, I do see student names. Screenshot shows part of student's name (privacy and all of that):
The only wrinkle that might explain this is that this assignment was given and submitted while I was using 2.7.2, then scored after upgrading to 2.8.1. So maybe that explains it?
Just an FYI in case anyone finds this worth exploring for possible bugs.