I think this is not true, in China are no restrictions on the production of chips, the Chinese always keep up with the production, they produce in tons.
The actual ASIC CHIPS are not made in China.
There are *4* foundries in the entire WORLD that are capable of making chips on the 14/16nm node - TSMC in Taiwan, Global Foundries in New York, Samsung in Korea, and Intel (I forget offhand where their foundry is at for this node, somewhere in the US as I recall).
*ALL* of those foundries are booked solid for MONTHS in advanced, and widely reported to be running the applicable lines at 100% capacity.
Intel doesn't sell capacity to "boutique" manufacturers like Bitmain (I'm pretty sure their only "non-Intel" production is for Apple), GF is overloaded by demand from AMD and IBM and their other smaller LONG-TERM-CONTRACT customers (one of the reasons AMD GPUs continue to be in short supply), Samsung rarely sells their capacity to ANYONE else (NVidia is a rare exception), which leaves most of the demand for "small" chip houses like Bitmain to TSMC.
Sure there are a ton of places that can make older node chips like 28nm and higher, but the ones that can make CURRENT STATE OF THE ART CHIPS like are used in the Bitmain S9 are overloaded by the demand.
DEFINITELY don't confuse production of generic PRODUCTS they can make at home in China like Steel and Aluminum with high-tech production of Semiconductors where they are GENERATIONS behind the current state-of-the-art.