i am not quite sure what you mean with olp license maybe you mean the license for the TeachPendant. This you need to create robot programs with the correct synatx of the robot (ABB, Kuka aso...) with a program download.
The RCS license is directly for the robot manufacturer (ABB, Kuka aso...). It is used in combination with a TeachPendant to simulate the robot with sane behaviour like the robot in reality.
Yes you can create a download without RCS, but it is possible that the configurations of your locations is not correct, because the motion behaviour of robot with RCS is different to motion behaviour of robot without RCS.
Sometimes it is possible to move to location without RCS without any problems. If you move to this location with RCS the robot is not able to do this.
Of course, for OLP it is better with RCS.