I've always thought, perhaps wishfully, that Alex from OXENFREE and her brother were originally intended as indigenous. I struggle to reconcile the conflict felt by Michael about departing his hometown with the late predominance of the indigenous in the Pacific Northwest. Settlers did not come to that region in great numbers until after the Civil War, if I recall correctly. And, without presuming the veracity of such a rhetorical motif, the indigenous are often portrayed in American Media as possessing a deep sentimental connection to the land.
Then there's the anomaly concerning the military career of the island's namesake–Edwards or whatever–which taunts Alex by comparing her fate to that of the indigenous slaughtered by him. This is a lot more personal, meaningful, and hurtful if my speculation is correct, as are Clarissa's remarks about Michael being “free” before he and Alex went on one last swim.