It is extremely unlikely that US prosecutors are after him for any alleged "backroom talk/act". WSJ reported that the charges against him “ may involve the Espionage Act, which criminalizes the disclosure of national defense-related information.”[0] Accordingly, the implications on journalism are real and far-reaching [1].

[0] https://www.wsj.com/articles/u-s-is-optimistic-it-will-prose...

[1] https://theintercept.com/2018/11/16/as-the-obama-doj-conclud...