There is. In fact it's called a "land port" for a reason, the park has a huge freight yard connected to 2 rail lines it's just not shown in this picture because it's shared infrastructure of the industrial park.
I don't think there is any railway link to the site, at least in the short term. Both of the two rail lines nearby are passanger only high speed (250 km/h to 350 km/h) lines (references: https://zh.wikipedia.org/zh-cn/%E9%83%91%E9%98%9C%E9%AB%98%E... , https://zh.wikipedia.org/zh-cn/%E9%83%91%E6%B8%9D%E9%AB%98%E... ). The train yard ~5 km north of the factory is 郑州南动车所, also a high speed rail depot.
That area is called 郑州港区 (literal translation Zhengzhou "port area", full name: 郑州航空港经济综合实验区) is actually for it's closeness to the airport (ZHCC). English reference: https://en.wikipedia.org/wiki/Zhengzhou_Airport_Economy_Zone .
Yeah I think so. Zhengzhou has perhaps the largest yard in China. The factory is there for a reason.