The cancelation, according to Autoweek, is due to a sale and related security measures. Lance Miller, the owner of Carlisle Events, said the car had been sold to a third party, and therefore has to be moved to an "undisclosed location," for "security reasons."
What that means isn't yet clear, though it's possible the buyer's desire to remain anonymous may play into the decision.
As of now, Carlisle Events isn't releasing any further information, and it is unknown when the car may make a public appearance in the future. Miller said in his public statement, "I have confidence the car will be well cared for, and we hope to have it back here in Carlisle at a future show looking better than ever."
For more details and a brief history of the Briggs Cunningham Corvette, be sure to read our coverage of the brief semi-public showing held last night.