The Pacific Islanders are more closely related to the Denisovians than any other people on earth.
New Lapita Find Re-dates Known Fiji Settlers (Jomon/Ainu)
"Staring out from an ancient piece of pottery, the mysterious face of a bearded man has given scientists a unique glimpse of what the first settlers of Fiji may have looked like."
"Preliminary analysis shows that the eerie-looking face consists of a prominent raised nose, the left eye and what might be eyelashes, said Roselyn Kumar of the University of the South Pacific's Institute of Applied Sciences"
From your third link:
“The researchers also concluded that the genetic data showed that the Polynesians and Micronesians were most closely related to Taiwan Aborigines and East Asians.”
Which is a bit more definitive than a single tall skeleton and one piece of pottery, so I’m unconvinced of your thesis.
It’s altogether possible that the current inhabitants weren’t the first settlers to the islands, though. They may have found other people already there when they arrived and just killed them or assimilated them without leaving much of a genetic trace.