Rumors about "Left 4 Dead 3" have been going around since the second iteration of the first-person cooperative game was released in 2009. The most recent speculation about the game was revealed by Master Herald, which says that a former employee from Valve Corporation leaked several pieces of information about the status of the game, particularly its development, plotline, and possible release date. 

According to the former Valve employee, "Left 4 Dead 3" will be developed as a prequel to the plot of the two earlier "Left 4 Dead" game titles. While the events of the two games are set in almost the same universe at the same time, the third installment is rumored to be set just one month after the infection from the pandemic outbreak became viral.

But the source also mentioned that the game developer halted the development of their other popular product, the first-person shooter game "Half-Life 3," so they can focus all their energies and resources on the development of the zombie shooter game. 

Other previous rumors about "Left 4 Dead 3" include new survivors, brand-new maps to explore, as well as an all-new story that will feature different periods in the timeline of the zombie apocalypse. There is also a report claiming that the six campaigns in the new installment are called Crash-land, Inquisitor Land, Impasse, Cliff-Hanger, Early Destination, as well as No Mercy.

While there is still no official news about the game's actual development, it would be safe to say that the first two sets of survivors will no longer appear in the new game. This means that Bill, Louis, Francis, and Zoey from the original game and Coach, Ellis, Rochelle, and Nick from "Left 4 Dead 2" will no longer appear in the upcoming game.