Is sharing a message criticizing a ruler and predicting the demise of his reign, then deleting it later, considered among the forbidden acts of rebellion against the ruler, and is repentance and a general supplication sufficient to lift the sin, and what are the implications of this if others have already viewed the post?

What the questioner said is not a rebellion against the ruler; rather, she spoke the truth when she said that the kingdom perishes or its owner perishes. Criticizing corrupt situations, clarifying the truth, and enjoining good and forbidding evil are not considered rebellion or defiance of the ruler. Defaming a Muslim ruler with the intent to disparage and criticize is forbidden unless it is intended for a public good, such as reducing evil and increasing good.