tl;dr: id Software and MachineGames released "Dawn of the Machine," a free 30th anniversary expansion for Quake featuring 19 new maps, a new soundtrack, enemy/weapon variants, and a looping episode structure with persistent upgrades. The update also includes engine improvements (reduced input latency, better interpolation), a cheats menu, and an id Vault with early development assets. It's available on Steam, consoles, and Microsoft Store, but not on GOG or Epic Games Store versions.