I wonder whether, in a few months when these children receive their First Holy Communion, a note will be sent home politely urging parents and guests not to receive the Eucharist on that day, so that the priests can spend more time with the children on their special day?
"Due to the large number of children, we ask all parents and guests to refrain from going to Confession today so the priests will have more time with your children on their special day."
Experience has taught me that, without fail, on days when you're hearing the first Confessions of little guppies, you'll also going to catch a Marlin or two who haven't been to the Sacrament in years. To send a note home like that is the same as saying, "Don't worry, you don't have to feel guilty or emotionally moved while your here. Feel free not to sit there and reflect on your life while these children go to Confession. Instead, please, strike up multiple conversations with the people sitting all around you, so that the children experiencing God's mercy for the first time get used to the lack of reverence that they'll encounter in sacred spaces.
You want to allow the children to go first, that's perfectly reasonable. But to then "close up shop" after the last child is absolved loses a great opportunity.