Is remorse a prerequisite for returning to Islam after apostasy, according to all scholars?

Regret is the greatest pillar of repentance. There is no disagreement among scholars that it is a pillar, whether in repentance from apostasy or other sins. The pillars of repentance are three: abstaining from sin, regretting it, and resolving not to return to it. The repentance of an apostate includes embracing Islam, regretting the apostasy, and resolving not to return to it. The regret for apostasy should be the greatest due to the gravity of the sin of disbelief. It is also mentioned in the Sunnah that a man apostatized and then regretted it, whereupon verses from Surah Al-Imran were revealed, clarifying the acceptance of his repentance.