For many, this version became the "archival" copy of the game. Because it stripped away the performance-heavy DRM and included the pre-order bonuses and Deluxe Edition content, it was the version people kept to ensure they could play the game at its absolute best without needing an internet connection or extra purchases.
Since you're looking for a "piece" on it—whether that's a summary of what's inside or a bit of context on why it mattered— Resident Evil 2 Update v20191218 incl DLC-CODEX
It ensured all the "What If?" scenarios (No Time to Mourn, Runaway, Forgotten Soldier, and No Way Out) were fully integrated and playable. The Context For many, this version became the "archival" copy
This included the "Original Ver." Soundtrack Swap, all the extra costumes (like the Noir and Arklay Sheriff sets), and the "All In-game Rewards Unlock" which gave you the infinite ammo weapons immediately. The Context This included the "Original Ver
This was the big headline. Many players found that the game ran smoother and loaded faster once the background DRM software was patched out by Capcom.