It is designed to blunt any accusation that Trump fired Comey because Comey was investigating him.
Not that it will do any good... The media will just say whatever it wants to say and the libs will scream about kittens being tortured unless Obamacare is saved from the Nazis who want to deport honor students.
And CNN just said that -— at least Jeffry Tubin
That it waas because Trump was under investigation.