Not sure why they say this is Tesla 'shifting their strategy for the plant to focus on supplying the Chinese market' (other than throwing shade/ implying demand issues). The plant was always going to serve a wider area.update:
From January 2019:
Shanghai Giga output is just for greater China, not North America. Affordable cars must be made on same continent as customers.
Shanghai Giga will produce affordable versions of 3/Y for greater China. All Model S/X & higher cost versions of Model 3/Y will still be built in US for WW market, incl China.