Valve is as elusive as G-Man when it comes to discussing its plans, which is hardly surprising considering all the "unforeseen consequences" over the years, i.e. the numerous versions of Half-Life 3 and Episode Three that have been canceled. Announcing a sequel only to publicly 180 would probably go down about as well as throwing a bunch of snarks into a crammed vent, so instead, the studio keeps quiet until a game is absolutely ready for launch. But that doesn't mean Valve is completely secretive.
Source 2 updates often contain references to its upcoming projects, like Neon Prime/Citadel (which became Deadlock) and 'HLVR' (which became Alyx). There isn't much of an effort to hide these, and dataminers like Tyler McVicker and Gabe Follower regularly share their findings with the community on what's happening with Half-Life 3 based on new strings dug out of Dota 2 and Counter-Strike 2 updates. The fact that we know there's a new Half-Life game following Gordon Freeman in development is testament to this, let alone the finer details — such as new Xen life, offworld locations and NPCs, engine updates like hair strand simulation, damage flinch types, and even a mood animation system....
