Some...disturbing implications to this declassification.
It means the Thresher's crew was alive for, and above crush depth, for nearly 24 hours after they lost contact.
The Navy knew they were alive, and tried to rescue them, then covered the whole thing up when they failed and the sub imploded.
The crew were stuck, alive, in a sub that could not surface and was slowly leaking/sinking.
The Navy lied to everyone about what happened, and not a 'small' lie either.
This...changes everything we thought we knew about the loss of the Thresher.