Yup. At this point, keeping documents classified makes little sense — if you want to protect the Mafia, or Cuba, or the Soviet Union, or individuals who worked in the US government. There is no good reason to protect anything like that. BUT if the institution of the CIA is in the business of taking out inconvenient US politicians, then that seems like something you might want to conceal from the public.
The Truth will come out—in time BUT there are still many unanswered Questions about the assassination of Lincoln! What happened to the missing pages of Booths diary? What about the Dalgren Letter? Did Lincoln order the assassination of Jefferson Davis? Why was Mrs. Surat hung?