A typical repack (e.g., “Firestorm 5.4.8,” “Tauri’s repack,” or community releases on Ac-web.org) includes:
Most 548 repacks have broken rated battleground queues for 1 player.
Some open-source emulation projects (like TrinityCore) claim clean-room reverse engineering: developers never touched Blizzard’s server code, only observed client-server traffic. However, repack authors who include pre-compiled binaries with non-open-source fixes cannot claim this protection.