"Is this description about the Wasteland? An era before it was completely overrun by the swarm?"
Lu Ban quickly thought of that civilization which had chosen to hang itself amidst madness.
Now, the mission also involved traveling to the early days of the Wasteland, and it seemed there might even be a chance to try and save the Wasteland.
Lu Ban thought about it and felt it wasn't entirely impossible to accomplish.
For instance, to ensure the closed loop of fate remained unchanged, even if he truly saved the Wasteland, he would have to isolate a region and let the insects live there, making sure "the past" him could accurately complete those missions in "the future" Wasteland.
Thus, he would indeed have witnessed the Wasteland's swarm and the fall of Future City, but that would be an illusion, a lie woven by "the future" him.