When you request revision on a post, the user gets a DM like this from the system:
The message says to reply if the user has questions but it is just a thread with @system. When the user replies it seems like it is just sent to the void of system’s inbox, no admin notifications or changes to the reviewable.
This is sort of trivial but I think it would make sense to either notify the admin in some way, include @moderators in the automated message, or remove the string entirely.