Coaches can still communicate with recruits during a dead period, they just can't do it in person.
https://www.ncaa.org/student-athletes/resources/recruiting-calendars
What is a dead period?
During a dead period a college coach may not have face-to-face contact with college-bound student-athletes or their parents, and may not watch student-athletes compete or visit their high schools. Coaches may write and telephone student-athletes or their parents during a dead period.