I am surprised seeing this too. It has been eons since my Dad used to tell me a lot of about NOT using ginger on pork, but garlic on both is not bad.
It's all about ginger and pork having a chemical reaction that is bad on the aspect of the yin/yang balance in the body as my dad explained it. It releases a certain chemical as well that when your immunity is low, could trigger some conditions adverse to health. From that info, never use ginger on pork dishes too.
My dad was born in the 30s, so I assume that his wisdom on this emanated from older generations handed down to him as well by a long line of cooks from our family.
Uses of ginger in pork dishes could be regional, or maybe the younger generations making the infamous NorthEastern sweet and sour pork FORGOT that the ginger in that dish wasn't raw when added in cooking but rather already in a commercially available ready-made sauce that that HAS the ginger in it already. IT IS IN THE SAUCE that was separately made. NOT cooked through with the PORK. Cooking the ginger with the pork is what releases what my Dad described as the culprit that needs to be avoided. Just to clarify. Hope I made some sense. This to me, as my Father passed on to me, I will retain in my future cooking wisdom. :-)