JA did not present the chess position frivolously. The fact that he chose to use chess indicates that he is on the same page with DJT & Q, who have been alluding to chess for some time now.
The position shown is delicately balanced and dangerous for each side. However, white has a serious problem, which is that the rook is trapped in the corner, with the knight blocking it. If the knight is moved, the black queen will capture the rook and the game is de facto over. Yet white MUST free the knight and rook or white will lose to superior force. The clear path forward, indicated by someone's chess engine, is to play pawn to rook 4. This forces action on the rook file, leading to the release of the rook from the corner prison.
That is the point of showing us the position–how to get the rook into the game. Assange is the rook, and he has been trapped for a very long time, clear into the end game. He is saying that he is either free or about to be freed, bringing information power with him that puts white into a winning position.