Here’s everything we learned about Left 4 Dead 3 so far. We've gone back through the last decade of Left 4 Dead 3 rumors to determine what was fake, what was plausible, and what those 'leaks' might be able to tell us. If this doesn’t prove just how starved zombie enthusiasts are for even the slightest hint of L4D3, then I don’t know what does. The lack of an official announcement from Valve hasn’t stopped people from creating plenty of hoaxes and fan-made ‘leaks’ in the last few years. But there have been many, many rumors to pore over.
As far as we know, there's still no Left 4 Dead 3, Valve even staunchly denied it in January 2020.