Video released today by Universal that officially "announces" that the park will be opening in 2021: https://www.weibo.com/tv/v/I7l2fnHH4?fid=1034:4417490638316795
Sources: https://m.weibo.cn/status/4417208371249796 and https://mp.weixin.qq.com/s/P5-ykB4j6EQVzSsxBJCj7Q