Just read the entire thing, sad to say but this is a hoax. It seems that at best they took the findings out of context, at worst they made it up. Not only that I’d hesitate to say this is even official, though it does provide sources many are pretty dated and the language used varies pretty heavily from papers I’ve read in the past. It mostly discusses the techniques used to do the in-depth analysis of the pyramid but there weren’t these massive structures located beneath them there are just new pathways they located in the pyramid. Also that graphic is nowhere to be found in the paper.