Is the gathering of Muslims by the Commander of the Faithful, Umar (may Allah be pleased with him), behind a single reciter considered evidence for the permissibility of reciting the Qur'an in the mosque on Friday?

Umar (may Allah be pleased with him) gathered the people behind a single Imam for the Tarawih prayer. The Prophet (peace be upon him) had previously prayed Tarawih in congregation but stopped, fearing it might be made obligatory for his Ummah. Umar's statement: "What a good bid'ah this is" referred to a linguistic innovation, not a religious one, as it was in accordance with the Sunnah. As for reciting the Quran aloud in the mosque before the Friday sermon, it is not legislated.