Sarawak and SG Chinese population has very deep culture link all the way back to 17th century, the first Chinese Republic (initially a group of mining colonies) was formed in 18th century in Borneo under guardianship of the Borneo sultanates and Qing Dynasty.
After Qing dynasty defeat in 1895 Sino Nippon war, Dutch expanded into Borneo, the Chinese republic is crushed and many of its subjects fled to KL, SG and Sarawak in early 20th century
One road one belt is just a modern iteration of many previous trade links that existed hundreds of years ago