Consider the following scenario:
You want to force the non-authoritative synchronization of SYSVOL on a domain controller. In the File Replication Service (FRS), this was controlled through the D2 and D4 data values for the Burflags registry values, but these values do not exist for the Distributed File System Replication (DFSR) service. You cannot use the DFS Management snap-in (Dfsmgmt.msc) or the Dfsradmin.exe command-line tool to achieve this. Unlike custom DFSR replicated folders, SYSVOL is intentionally protected from any editing through its management interfaces to prevent accidents.
Microsoft Link: https://support.microsoft.com/en-us/kb/2218556