Well....even though the game isn't considered canon to the PnP Vampire, Caine was in LA for a time shortly before Gehenna ( see the last Vampire novel ).
The sarcophagus on the other hand is a "McGuffin" as Alfred Hitchcock called a powerful or useful item around which the plot of a story evolves. The McGuffin doesn't have to be important but everyone in the story thinks it is, and so reacts accordingly ( a few classic examples: The One Ring in Lord of the Rings, the Ark of the Covenant in the Raiders of the lost Ark ).
MacGuffin - Wikipedia, the free encyclopedia
Jack did a classic Con on everybody!