Blocking a communication from generating?

Is there a way to pre-emptively block a communication from being generated and going out to a student?

Our situation is that we have a daily 3C Engine job that looks for anyone who had an Enrollment Request (Enroll, Drop, Swap, Enroll from Waitlist), followed by a Comm Gen job that sends out an email to the students with their updated class schedule.

If for example a staff member accidentally dropped a student from a class and then added them back in, the student would get the email that night and might be confused. Is there any way to tell either the 3C engine or the Comm Gen process to ignore the student when the job runs that night? The only way I could think of would be to build into the selection query a service indicator used specifically for this purpose, but that seems kind of inelegant. I didn't know if there was something better I was missing.