Yes, cell phones could aggravate a lousy situation as described above.
But cell phones didn't cause the basic problem nor will a ban on them cure it.
The real problem that must be dealt with is why people are getting into these nasty fights in the first place. Fighting is wrong. A secondary concern is the idea of calling in family reinforcements. That suggests a very bad family attitude that needs to be addressed. It would seem to me if a fight broke out I'd use a cell phone to call the cops, not call for more fighters.
Kids who want to fight have found ways long before cell phones. Rumors of a big "rumble" would circulate well in advance.
The administrators need to deal with their gangs and violent prone students.