The long history of the Chinese practicing Buddhism and Dorje Shugden goes back a long way. In these modern days, it is only shown that China has got reconnected back with their faith that they had many many years ago. And I believe that it is a good thing.
It is true that China government is supporting the growth of Dorje Shugden because it is against the Dalai Lama and CTA. But I doubt that the Chinese citizens in China would also practice Dorje Shugden for the same reason. To me, I think that they continue to practice Dorje Shugden and they like it is because they really do see and feel the effects of their prayers. Showing to them that Dorje Shugden is really a Buddha that answers their prayers and help them irregardless of what happens. Hence, having that faith and devotion towards Dorje Shugden.