Why people are talking about Half-Life 3 and Left 4 Dead 3

https://www.youtube.com/watch?v=g2igP0jguSc
What's new this time? The files within the Source 2 game engine build that's a part of the performance test include references to Half-Life 3 and Left 4 Dead 3, two games Valve's legion of fans are desperate to see one day come out.

In the video below, Valve News Network runs through this latest "leak". It's clutching at straws, as Half-Life 3 rumours tend to, so don't get your hopes up. But who knows? At this point I wouldn't put it past Valve to deliberately put in references to Half-Life 3 in its builds just for shits and giggles.