It helps to consider the big picture.
The panamera taillight is just a taillight. It doesn’t incorporate both a high voltage charge port and a motorized charge port door.
The S tailight is more complex. Installing it, as part of the high voltage system is not something a lot of people will be willing to DIY. There isn’t a massive network of shops willing to do the work either.
Porsche owners are also notorious for paying big dollars for unique parts. They’re a large and well established supply of shops who will swap the taillights. Almost any owner could do the swap themselves if they wanted.
Lots of model S parts being made in china, yes. Not a single taillight in 10 years.