You should see boarding at Narita... literally everybody and their mother is Sky Priority... There is even a long line of Diamonds... This is the effect of airline consolidation, a lot of offshore business in Asia, an expansion to SkyTeam, resulting in a ton of Gold or SkyTeam Elite Plus. In addition, when you buy Comfort+, you also get Sky Priority...
You are not wrong, a ton of elites fly into and out of PVG. I am one of them - tehe
By the way, having spent a few years on UA as 1K, you've seen nothing yet wait until you see boarding at SFO. Holy Cow, there is even a line for UA Global Services. Combing global services and 1K, it's like 60% of the plane, and that's one level above Sky Priority. On Asia-bound flights at UA out of SFO, it's actually hard to find someone that doesn't hold status.