What is the significance of this leak? As far as 9/11 goes, this small leak of information is only the tip of the iceberg when it comes to what really happened on 9/11. So, why leak only about Saudi involvement?
Because of US oil fracking, the US is unbelievably nearly oil independent right now. The US has had a dependance of Saudi oil for decades and now it seems we are okay with "burning the bridge" with Saudi Arabia. Saudi Arabia is threatening to pull out all it hundreds of billions of dollars from the US economy if the US goes any further in revealing its involvement in 9/11 or gives US citizens rights to sue them.
The 9/11 Bill that the US Congress is considering and Paul Ryan and Pres Obama are blocking, would give US citizens the right to sue Saudi Arabia for their involvement in 9/11. This bill doesn't mean victim families would get any money, but it would open 9/11 up to a wave of independent investigations which it never had before.
The 9/11 Papers put the US in a terrible economic predicament. China has just launched its gold-backed Yuan which it will not exchange with USD or any other non-gold, fiat currency. If Saudi Arabia pulls out hundreds of billions of dollars from the US economy, it might be enough to throw a US economy already on QE-life support into another 2008 crisis.