I definitely think this is an impactful source, but I wouldn't call the drops a dump. Bitcoin hasn't really dropped under 13000 as far as I've seen, and until I see it drop much more, I would never consider Bitcoin to be dumped. It's not like there's a few people just pumping/dumping as there are with many altcoins.

However, I do think China's extreme intervention is definitely pulling the price down. They've had a significant impact on the BTC price in history, so this crack down on miners affects bitcoin's confirmation times and whatnot. I've heard that China is rumored to be making their own centralized crypto currency itself, which may explain why they're making such strong moves against BTC.