Despite some cryptic teasing, Valve confirmed that Left 4 Dead 3 isn’t something that they’re working on at the moment.
I somehow completely missed these strange Left 4 Dead 3 tweets. However, even if I didn’t, there’s no way in Hell Valve would work on Left 4 Dead 3. Not now or anywhere in the close future. Why? See, the previous game released 11 years ago. Yes, Left 4 Dead 2 is that old, it’s strange but that’s how it is. Do you know how many players this old title has? The average player count these last 30 days was around 12 000. Not a bad number. Do you know why so many people still play this co-op zombies game? Because Valve nailed the formula with the second game.
You won’t find many people that don’t immediately recommend this title if you look for a good co-op experience with some friends. Especially if you like shooting and zombies. With that in mind, would Valve have a reason for making Left 4 Dead 3? See for yourself:
“It’s clear some people are having fun creating misinformation to spin up the community and other outlets. Unfortunately, for now a new L4D game is not something we’re working on.”
That’s their official statement which you can see in this IGN article. So no, Valve isn’t making a new Left 4 Dead game. They’re too busy with Half-Life: Alyx as is.