Smells like BS.
Read the entire article. Very provable.
The headline and lede are, that's for sure.
NSA Blocks Release Of Loretta Lynch-Bill Clinton Airplane Tape For 'National Security', the source for the claim, has the same problem, but at least cites language of the purported refusal to respond to the request.
"To respond to your request, NSA would have to confirm or deny the existence of intelligence records on Loretta Lynch," the agency stated in its FOIA response on November 14, days after the election. "Were we to do so in your case, we would have to do so for every other requester. This would enable, for example, a terrorist or other adversary to file a FOIA request with us in order to determine whether he or she was under surveillance or had evaded it. This is turn would allow that individual to better assess whether they could successfully act to damage the national security of the United States. For such reasons, we can neither confirm nor deny the existence or non-existence of the records you requested."
Either that or the NSA was spying on Clinton and Lynch.