So, going to dox myself since there are likely under 50k of us on earth, but I'm palauan. I told my malaysian colleagues this and they mentioned this very thing to me about the word pulau. Palau is anglicisation of the palauan world "belau" although the 'b' can be a soft 'p' or vice-versa in the language depending on the word.

I haven't learned too deeply about what athropologists generally think of palau's original settlement and the carolines in general but likely my ancestors were part of the Austronesian migration as other commentors said, although most of the maps I see show it coming from the philipines instead of indonesia/malaysia, so it might be from the same original source albeit on different branches. We share some similar words (babii=pig and I find a striking similarity between "makan" and "mengang" which is palauan for "eating") but the language structure seems quite different to me than bahasa melayu/bahasa indonesia generally. Also, given the cross colonisation/migration of colonised people as labourers from before WWII, I'm not really sure which words are palauan or just imports from SEA generally in the modern era after european and japanese contact. For example, we eat rambutan which we call "rambotang" although I think the fruits were just imported by the colonisers.

That said, I now live in singapore and the first time I saw images of Batak houses it was jarring because they look a hell lot like our traditional chief houses called "bai" [1], and I had never seen anything else like them in elsewhere in the world. Due to historical reasons since the end of WWII we don't have many dealing with indonesia today.

[1] http://underwatercolours.com/travel-tales/the-palauan-bai