7.5.2.1 states that the requirments of 7.5.2 apply to all processes. Regardless of whether they are mandated by customers or not. But if you look at the requirements of 7.5.2 and the requirements of 7.1, you will find a lot of similarities. Most of 7.5.2 is already considered during the quality planning stages, so there should be little additional work for 7.5.2.