On September 20 construction officially started on the theme park and hotel itself (previously groundwork was taking place plus construction of the RD&E area).
Sources: https://www.sbc-mcc.com/media/cn/details/114713 and https://www.sohu.com/a/722649139_823359 and https://mp.weixin.qq.com/s/JcMDcnm41IBQvSK40vV3GA and https://mp.weixin.qq.com/s/VjwiMrEypt_aEmxHnkkoUA