It's for caching files related to apex and i think mod plsql calls
If we cached those security checks,I think bad things could happen.
Agree with you maybe caching ords roles is not the best idea. However downloading definition od PL/SQL REST every time, querying the definition of a procedure from LOB column is quite an expensive way (maybe ist is very safe but also ho negative impact). When I want to change definition of REST I can still peform a warm restart of all weblogic nodes