Indeed, if the question is merely whether the President or the CIA should decide which information remains secret, I would under ordinary circumstances say “The President, of course.”
In this case, however, we have a President who has repeatedly demonstrated that his only value is self-interest and an Attorney General who has made it clear he believes his only duty is to protect the President and that, in any case, the President is above the law. That rather changes the equation.
I have no doubt that the FBI and/or CIA investigated Russian interference in the 2016 election and any possible coordination with the Trump campaign. Indeed, we were repeatedly told during the campaign that multiple US intelligence agencies were sure Russia was illegally interfering, including by hacking into the computer systems of various Democratic operatives and leaking embarrassing information.