Is fasting during the day, concluded by reciting the Qur’an at night, considered an innovation?

There is no evidence for the permissibility of dedicating the day of completing the Qur’an to fasting. If someone fasts it out of gratitude to Allah, that is good. However, it should not be done as if it were a Sunnah, nor should it be adhered to, because adhering to a specific act of worship at a specific time for which there is no religious proof is considered an innovation (bid'ah), such as fasting and praying on the night of the 15th of Sha'ban.