Isn't saying that the apostate who called for disbelief and caused others to apostatize has validly embraced Islam, without stipulating that he must call back those whom he caused to disbelieve, contrary to the Almighty's saying: (Except for those who repent and correct themselves and make [things] clear. Those, I will accept their repentance; and I am the Accepter of repentance, the Merciful)?

The Fatwa's Summary:

For the repentance of one who called to disbelief or innovation to be valid, it is not a condition that he call back those who went astray because of him. Rather, the conditions of repentance are: abstaining from the sin, regretting it, resolving not to return to it, and restoring any injustices. As for the Almighty's saying: (Except for those who repent and correct themselves and make clear [the truth]), this applies to those who concealed the description of the Prophet, peace and blessings be upon him, and hid his prophethood; their repentance is to make it clear. Sincere repentance is accepted even if the repentant person does not clarify [the truth] to those whom he led astray.