That 58 gigawatt goal for 2020 was already less ambitious than the goal of 70 GW by 2020 from 2012.
"China may resume approving nuke plants in H1" (January 2012)
https://www.reuters.com/article/china-nuclear/china-may-resu...
The government will resume approving new plants after the announcement of the nuclear safety plan which recently won clearance from the Ministry of Environmental Protection (MEP), the China Securities Journal said.
The report also said in order to meet the government-set target of having non-fossil fuels to supply 15 percent of China’s primary energy use by 2020, the total installed nuclear capacity should not fall under 70 gigawatts (GW) by then.
That in turn was less ambitious than the 2020 nuclear goals China had before the Fukushima accident.
"Nuclear power to rise 10-fold by 2020" (July 2009)
https://www.chinadaily.com.cn/china/2009-07/02/content_83464...
China is planning for an installed nuclear power capacity of 86 gigawatts by 2020, up nearly 10-fold from the 9 GW capacity it had by the end of last year, two people familiar with the matter said.