That will cause lots of juristic issues. Dual citizenship makes sense for EU, because the countries are small, and traditionally, differences are not that wide.
However, what I DO have problem with is that Chinese lawmakers put PRC citizenship at the LOWEST priority - automatically waive your citizenship as soon as you obtain another citizenship. They should take a page from lots of other countries including US - as long as you do not EXPLICITLY request to remove your citizenship of your birth country, we will treat you as our citizen, meaning, protect you with OUR LAWS and force you to OBEY our laws.
But then again, that BS rule was introduced in the Mao years, when CCP wanted to make friends with other South-East Asian countries, so that they wouldn't have had any concern to mistreat oversea Chinese. Sigh, 中国人民从此站起来了。。。