When someone in authority 'suggests' you don't do something, even if they can't 'order' you not to do it, the inference is that you'd better not, or else. While there was no official ban in place, it was clear that putting on a performance in the vicinity of the keraton was a no-no. The suggestion not to do it was practically an order, even though the person making the suggestion didn't have the official authority to ban it.