Departure from expectation is not limited to changing pronouns. A future event may be expressed through a past-tense form to present its occurrence as certain or vividly realized.
وَيَوْمَ يُنْفَخُ فِي الصُّورِ فَفَزِعَ مَنْ فِي السَّمَاوَاتِ وَمَنْ فِي الْأَرْضِ
On the day the Trumpet is blown, those in the heavens and on earth will be terrified.
The past form «فَفَزِعَ» alongside «يُنْفَخُ» calls for attention. The future event is presented with the force of something already accomplished, stressing certainty and vivid impact.