The current political fallout does not mean the term is vanishing from daily Korean life. It simply means that clear boundaries, long ignored by powerful figures, are being re-established with zero tolerance for ambiguity.
The appropriate use of oppa remains confined to genuine private life: your actual older brother by blood, or a long-term male partner with whom an intimate dynamic is mutually understood. Outside those two clear boundaries, the word carries serious risks.
Using the term with a male colleague, an office manager, a client, a university professor, or an elected official breaches fundamental professional boundaries in Korea. It signals either an improper demand for personal favors or a total disregard for professional decorum. For cross-cultural communicators, foreigners working in Seoul, or business professionals managing regional teams, standard etiquette is simple: stick entirely to formal corporate titles (Bujang-nim, Daeri-nim) or append the universal respect marker -nim (님) to the person's full name. Doing so maintains clear boundaries, enforces mutual respect, and avoids the toxic entanglement of pseudo-familial politics.
