A likely feature list for that specific update would include:
: An essential DLC for fans of the 1998 original, allowing players to swap the modern dynamic score for the iconic classic soundtrack and sound effects. Why "CODEX"? residentevil2updatev20191218incldlccodex
If you want the full Resident Evil 2 experience legally, purchase the game from Steam, GOG, PlayStation Store, or Xbox Marketplace. The official version includes all post-launch updates and DLC through the "Deluxe Edition" or "All-in-One" DLC packs. A likely feature list for that specific update