MC1384415 — Microsoft Purview | Endpoint Data Loss Prevention now supports a pre‑curated file extension list

Microsoft Purview Endpoint DLP now uses a pre-curated list of supported, scannable file extensions for policy configuration, improving accuracy and enforcement consistency. Free-form entry is removed; unsupported extensions must be managed via a specific feature. Rollout begins mid-September 2026, with no change to existing protections unless policies are edited.