Gah, I phrased it poorly. The link I provided is, as best I can tell, using it in the sense of not yet in school, literally pre-school, not about a year before

Gah, I phrased it poorly. The link I provided is, as best I can tell, using it in the sense of not yet in school, literally pre-school, not about a year before Kindergarten as it is sometimes used and as my phrasing implies.