Not everyone, but yes, probably the majority of Chinese Indo speaks (or at least can listen to) Fuchienhua.
This is due to the course of immigration that took place a bit more or less 100 years ago. Some just looking for better lives, while some are avoiding war and political unrest. Some from Fuchien, as you might have guessed, some from other area (the most famous one is Hakka). They landed on different area, thus creating different dialects. For examples, Chinese Indo in North Andalas and the ones in South Andalas both speak Fuchien but their dialects have been somewhat mixed up with local dialect. Chinese Indo in Halang island will speak Hakka, while most of the ones in Jakarta (really born here) will almost lost the ability to speak any Chinese branch of dialects.