What is the ruling on a unified Friday sermon in all mosques of the state, given the differing needs of people and regions?

The unified Friday sermon is permissible if it includes the required pillars, especially if it is for a specific occasion and benefit, without adopting it as a permanent tradition. However, unifying the sermon continuously is not from the Sunnah (definition) of the Muslims; it is an innovation (bid'ah). Indeed, the practice since the time of prophethood has been for each preacher to deliver a sermon that suits the condition and needs of the congregants.