When Dutch people arrived in what is now Indonesia in the 16th century they ran into Chinese merchants- the only locals who could keep up their mercantile endeavours.
The Nanyang community is not uniformly pro-PRC.
A massive portion of them have blood and political relations with HK and Taiwan, and the younger generations don't have the same level of attachment to China as older less educated Nanyang Chinese do.
You can see this in Singapore and Thailand, with Millenial/GenZ Nanyang Chinese who can't even speak Mandarin anymore and almost entirely consume Western media.
In Malaysia, PRC nationalism is stronger, but that's in reaction to horrid race relations between Chinese and Malays/Bumiputera due to policies like "Ketuanan Melayu", memories/experiences from the various race riots of the 1960s-70s, and also the insularness/otherness of the Chinese community compared to other communities in Malaysia.