"invited to the cookout" comes from African-American Vernacular English or Multicultural London English and means of an outsider, supportive and understanding of african americans to such an extent as to be considered an ally. It has spread well beyond its origin through hip-hop, drill, TikTok and gaming, so a teen of any background may use it. It is not in itself a sign of bad behaviour; it is a style of speech the way 'cool' or 'wicked' once was. The conversation worth having is about respecting where the language comes from, not about banning the word.