You hit the nail on the head. This is old news; they've been investigating this for years.
They chose now of all times, with the protests going on in Cuba and U.S. officials openly calling for U.S. intervention, to release another presser about a years-old story which gins up negative sentiment against Cuba.
"In a wide-ranging, exclusive interview with NPR's Mary Louise Kelly, Burns also discussed the CIA's future in Afghanistan and the theory that the coronavirus outbreak was caused by a leak from a Chinese state-run laboratory in Wuhan."
This was not a random press conference organized just to loud speak the words "Havana syndrome". It's almost like you didn't even read the linked article.
They chose now of all times, with the protests going on in Cuba and U.S. officials openly calling for U.S. intervention, to release another presser about a years-old story which gins up negative sentiment against Cuba.