This is also a feature that I would like... In the meantime, I use a column formula to hide the user's name:
=IF(LEN([Latest Comment]@row) > 0, RIGHT([Latest Comment]@row, LEN([Latest Comment]@row) - FIND(" - ", [Latest Comment]@row) - 2), "")
This basically determines the position of the " - " string and trims this section from the comment.
Hope this helps!