%ISOPEN, %FOUND, %NOTFOUND variables aren't useful at all in CURSOR FOR loops : Implicit Cursor « Cursor « Oracle PL/SQL Tutorial

The CURSOR FOR loop is always closed before and after the loop and open inside the loop.

There is no reason to ever use %ISOPEN.

Inside the loop, records are always found, so %FOUND is always true inside the loop.

Outside the loop, %FOUND, %NOT FOUND would return an error.