Ironically, I feel like Hawaii would be one of the few place probably untouched or barely touched by the nukes because it doesn't have as much importance to the US and its so far away from the main land. Not trying to disrespect Hawaiians or anything like that, I'm just saying that what would anyone have to gain by nuking Hawaii?
But it's close to Asia. I'd imagine the Fallout version of Hawaii would be even more chock full of military bases than it is IRL - an important strategic asset and refueling/re-supplying depot between the mainland and the war front in China. If we did want the Fallout series to go to Asia (which I honestly can't see happening, given the America-centric nature of the setting), Hawaii would be a logical bridge. I think
Fallout: Oahu is a lot more likely, and in keeping with the setting, than
Fallout: Seoul.
I agree Hawaii probably escaped the worst of the devastation, although between the wind and the ocean, plenty of radioactive material probably found its way there, leading to unique mutations. Because it's so remote, it would be interesting to see what kind of societies emerge there, and with all the prewar weapons lying around, each island could be a separate little fortress, each warring against each other not unlike the ancient Hawaiian kingdoms.
And if a powerful faction on the mainland was aware of Hawaii's existence, imagine the motivation for getting there: a fertile land, almost untouched by the scars of the war, and sitting on a gold mine of prewar military tech. I could imagine a Brotherhood outpost or the NCR trying to fix up an old ocean liner or a submarine (or just using a Vertibird) and sending there out on a scouting mission. The vessel gets shot down by one of the local factions and everyone on board dies except the player character, who emerges and must make their way through the islands.
And who knows, maybe groups in Asia or Australia or elsewhere have also heard rumors of this paradise and also want to seize it for themselves?