Does reading the last verses of Surat Al-Kahf before bed guarantee waking up for Fajr prayer?

The Prophet (peace be upon him) warned against innovation in religion, and that every innovation is a misguidance. It has not been authentically established in Islamic law that reciting the end of Surat Al-Kahf before sleep has a specific virtue, or that it helps one wake up for Fajr prayer. What has been authentically established from the Prophet (peace be upon him) are certain remembrances to be recited before sleep, and the end of Surat Al-Kahf is not among them.