Very doubtful and unlikely. China, like the other East Asia countries, is very serious about preserving its culture and they see the cautionary tale that Europe has become. Not sure how much the author knows about China and the Chinese.
Even just starting by making a comparison to the UK to extrapolate how many immigrants China could absorb strikes me as odd: The Chinese are actually horrified by the result of mass immigration in Europe and the UK. Mass immigration as obviously good and inevitable is a purely Western "dogma" and in fact the Chinese even have an expression for this left-of-centre ideology in the West: 白左, which means "white left" [1]. The Wikipedia page has a strangely orientated description but it is true that it is quite widespread among Chinese who live or have travelled extensively overseas.