Yeah that's just the nature of prep basketball now. Basically every highly ranked kid leaves and goes to academies for high school.
Boswell reclassed so he spent 2 years in California and 1 in Arizona after growing up in Urbana. I think it's safe to say that he was a hometown kid for Illinois since youre going to grow up in that environment and develop sports allegiances before high school.
Similarly I would call Buzelis a hometown kid for the Bulls since he grew up in the suburbs and was likely a bulls fan before going to a prep school in Kansas.