Not everything is clear/confirmed yet but apparently Sunac will now be involved in the development of at minimum Six Flags theme park Six Flags Hurricane Harbor in Haiyan, Zhejiang. The resort destination might be rebranded to Hangzhou Bay Sunac Cultural Tourism City. It is assumed right now that the Six Flags name/rebranding will remain so Six Flags and Six Flags Hurricane Harbor will be located within/a part of Hangzhou Bay Sunac Cultural Tourism City. Construction has officially resumed on the parks in Zhejiang and Sunac plans to first open the waterpark in July 2021.
Newly released concept art of Hangzhou Bay Sunac Cultural Tourism City:
Sunac's involvement in the other Six Flags parks planned for Chongqing, Nanjing, and Fuzhou are not confirmed but likely. If Sunac does end up developing the parks in Chongqing, they will be about a half hour drive from the Chongqing Sunac Cultural Tourism City which is about to open.
Sources: https://m.weibo.cn/status/4511335709629998 and https://baijiahao.baidu.com/s?id=1653065117167425790&wfr=spider&for=pc and https://finance.sina.com.cn/chanjing/gsnews/2019-12-16/doc-iihnzhfz6287338.shtml and https://www.hotbak.net/key/%E8%9E%8D%E5%88%9B%E5%B0%86%E5%8F%82%E4%B8%8E%E5%BC%80%E5%8F%91%E6%B5%B7%E7%9B%90%E5%B1%B1%E6%B0%B4%E5%85%AD%E6%97%97%E9%A1%B9%E7%9B%AEZAKER%E6%96%B0%E9%97%BB.html and https://mp.weixin.qq.com/s/tGG8y4KzGGG_Uj5jQDImig and http://zjrb.zjol.com.cn/html/2020-06/02/content_3334996.htm