I can speak as a former kindergarten teacher. This would be one of the happiest days of school for kids as they prepared for Christmas and their holiday break, as they sang songs, put on performances, made decorations and brought me small, sweet gifts. Everyone would be in high spirits, not much real classwork would be getting done, lots of laughter and happiness.
THAT is what a kindergarten class is like at this time of year...... and to replace that image with one of all of those innocent children slain is just horrific, beyond horrific.