Is it necessary to inform the congregants about what happened regarding the interruption of the intention of imamate, followed by the imam's silent pronouncement of "Allahu Akbar"? And is it sufficient to act upon the fatwa of the Shafi'i school of thought in a situation of hardship, or was the prayer not interrupted in the first place?

He who is afflicted by whisperings during his prayer should ignore them and continue his prayer. If he speaks during the prayer or breaks his intention, his prayer becomes void, unless he is overwhelmed and unable to control himself. As for the congregants, their prayer is not invalidated by what happened to their Imam, as long as they were unaware of it, because it is a hidden cause that does not prevent the validity of following him, and the Imam is not obliged to inform them of it.