Kings did not summon random soldiers. Before you keep that appointment, you would want to know why. If the king intended to execute you, you would want to know so that you could fail to show up for the appointment. In any case, it is clear from the story that Uriah finds out what’s up before he sees David: “When Uriah came to him, David asked him how Joab was, how the soldiers were and how the war was going. Then David said to Uriah, ‘Go down to your house and wash your feet.’ So Uriah left the palace, and a gift from the king was sent after him” (2 Sam. 11:7-8).
