The trend of teaching content previously taught in 1st grade to kindergartners or even preschoolers is known as

push down curriculum

Explanation:

Over the past few decades, observers say, preschool classes and kindergartens have begun to look more like traditional 1st grade classes: young children are expected to sit quietly while they listen to whole-class instruction or fill in worksheets. Concurrently, teachers have been expecting their pupils to know more and more when they first enter their classrooms.

Experts cite many reasons for this trend. The urge to catch up with the Russians after the launching of Sputnik led to "young children doing oodles of sit-still, pencil-and-paper work"-a type of schoolwork inappropriate for 5 - to 7-year-olds, says Jim Uphoff, a professor of education at Wright State University in Dayton, Ohio. (Today, the urge to compete with Japan yields the same result, experts say.) Another cause of the pushed-down curriculum is the widespread-yet incorrect-notion that one can teach children anything, at any age, if the content is presented in the right way, says David Elkind, a professor of child study at Tufts University.