[DougWebb]

I'm going off memory here, but I believe the link is that some moai have arms and hands still visible, with the hands holding the belly. This same detail is also visible on some other ancient statues, including some at Gobekli Tepe. It's a specific detail that you wouldn't expect to find so similarly in carvings so unrelated.

[wood_spirit]

An off the cuff plausible explanation is that sticking out arms are challenging because they would easily break off due to gravity etc, whereas arms touching the body are straightforward. So we end up with statues that are very vertical all over the world because it’s easier.

[earlyam]

That doesn't seem so specific to imply a connection. For most of human history we spent our time trying to not starve. Hands holding a contented belly seems like a universal symbol.

[aprinsen]

Also could be a pregnancy/fertility motif?