August didn't really have time to leave a message for people to see before he vanished, but their plan for the time before the third stage began was thoroughly fleshed out, so there wasn't a need for them to have someone giving direct orders.
One would expect there to be complaints about such a sudden disappearance, but everyone on the team was at least a little perceptive.
August had left to find troops to make up the other half of their army. Until he came back with good or bad news, nobody was going to say anything.
His most fierce opposition came from Raphael and Iridia, but they were especially understanding in this case. Raphael was the one who pushed the responsibility onto August in the first place, so he had the least right to complain.
