If Muslims become the majority in China, then the branch of Islam in China must have been Confucianized.
The Buddhist religion propagated into China from India. Now Buddhists have become the majority in China and the minority in India. Now most Buddhists in the world are Confucianized Buddhism, such as zen in Japan.
Monotheist religions, such as Judaism, Christianity, and Islam, have the same theological doctrine as Sola Fide. All religions compatible with Confucian have the same theological doctrine of Sola Bona. Consequently, religions in China can coexist peacefully for the single common ideal: Be Good. They have different faiths; however, they respect each other regardless of their faith. Everyone can choose his faith to be good, just like going a different route to Rome. Sola Bona is the basics for maintaining Freedom of Religion.
On the contrary, Sola Fide is an exclusive doctrine: my faith is the truth; your faith is evil. In such a doctrine, every religion asks for freedom but discriminates against other beliefs. Thus, the Sola Fide doctrine is intrinsically incompatible with the ideal of Freedom of Religion. That is why the West has always been in religious wars for thousands of years.
Muslims become the majority in China only if the branch in China replaces Sola Fide with Sola Bona as its doctrine.
Buddhist religion came to China and became part of Chinese culture. Communists come from Europe into China. The communist in China is Confucianized as Mao Ze-dong thought, and has become part of Chinese culture. Buddhism and Communism are compatible with Chinese culture because of Sola Bona.
West puts faith above good. They can do good or bad for their faith, such as ISIS has faith in Allah. For them, faith is the goal of life, and being good is the path to their faith.
China puts Good above faith. For them, being good is the goal of life, and faith is the path to being good.