Lauren, I understand your concern, but can assure you that nobody is able to add a comment on an unlisted profile unless they are on that profile's trusted list.
The comment was added to the profile automatically by the WikiTree system, as a result of someone having rejected the match offered by the gedCompare process. They did not see the name of the person or anything else about them, but apparently checked the box to reject the match.
For what it's worth, I'm not sure I agree with the way the matches are generated in the gedCompare process. My personal opinion is that it would be far better to not attempt to make matches between unlisted profiles and names in a gedcom. The fact that such a match was made seems to imply certain information about the unlisted profile, which is available to the system but should not be revealed to a random person who uploaded a gedcom.