It seems the suggestion has been made that the Hawaiians and some of the Polynesian cultures en route to Hawai'i only brought with them the most prized, kavain-rich, easy-to-drink cultivars and deliberately shunned high DHM varieties. While this certainly seems to be true at present, judging by the most common varieties currently available to us from these regions, does this following quote suggest it was not always the case:
The research for this book was done in 1980's and '90s. So, only a few short decades ago it was acknowledged that there are cultivars from Hawai'i and other Polynesian islands that are equal to cultivars from Melanesia (Vanuatu/New Guinea) and are blatantly low in Kavain and extremely high in DHM and DHK. Being that this was only 20-30 years ago, it's probably safe to assume that if you extrapolate back even further, there was even more diversity in cultivars/chemotype groups in regions you wouldn't currently think so...or at least that these less common varieties, for the region, were once more common. Who knows what was lost to time, western contact, missionary bans, weather patterns and cultural changes.