What is the ruling of Islamic law regarding someone who created a new row between the Imam and the preceding row, after moving the sutrah and the Imam asking to move forward, due to the existing row not being sufficient for the worshippers?

The prayer of these individuals is valid, and the sutrah of the Imam serves as a sutrah for those praying behind him. Therefore, the movement of someone between the rows for a need, or the Imam moving the sutrah and advancing towards it, does not cause any harm. All of this is permissible and is for the benefit of the prayer.