I will speculate that many Pacific islands were connected, or within visual distance, during our current 2.6 million year Ice Age.
During our last glacial period, which ended about 11,000 years ago, Pacific Ocean sea level declined about 300 yards.
Some were, most weren’t.
“during our current 2.6 million year Ice Age.”
Aside from the topic of sea level rise, are you sure this number is right?
In just the last million years alone there have been at least 8 full Glacial/Interglacial cycles... A full cycle peak to peak happens approximately every 124,000 years...