RSSYes, many more would have died have they not fled, whether Southeast Asia was under colonial rule or not at that time. The Chinese settlers were mostly coolies back then, and most of them end up working in ruinous conditions in the early days. Yes, a small but significant minority got rather rich by venturing into entrepreneurship, and some of them are quite shoddy, admittedly.
The part where CIA is accused of complicity is in the 60’s instead of the 90’s, when the main contention revolved around Communism and religious anti-Communist reaction.
The rest of Asia had been trading goods way before Marco Polo was born.
For example, check out the empire of Srivijaya and its trade routes: https://en.m.wikipedia.org/wiki/Srivijaya, and the history of the Silk Road:
https://en.m.wikipedia.org/wiki/Silk_Road