It is based on your target ESD level.
It is a real suggestion from foundry to achieve foundry's guaranteed ESD level. (because of weak break down vlotage in advanced process even IO device is employed.
Maybe it is not neccessry if you don't have conmercial ESD requirement. You may need ESD enginner to evaluate ESD level if you don't use cascode MOS; and the level is relevant to your whole chip ESD plan/architecture.