That "review" thing sounds kind of bizarre to me. What kinds of things do they ask? Like letter and number identification? Days of the week?
"Developmentally appropriate instruction" is a concept that all right-minded early childhood educators cling to.
And pouring facts into children (like water into a pitcher) and seeing how much they can parrot back is NOT appropriate for preschool. Nor is the "drill and practice" of flashcards, or "learning by rote." (Actually, it's not a good method for teaching any age group, including adults, but I digress.) At the preschool stage, is all about exploration, make believe and playing. Check out "Einstein Didn't Use Flashcards" by Kathy Hirsh-Pasek, PhD., and Roberta Golinkoff, PhD.
Numerous studies have shown that children who are enrolled in preschools and kindergartens that stress academic and didactic instruction become *less* creative than children who are in programs that emphasize playtime and make believe. "Play is the work of a young child", as Jean Piaget said.
"Kindergarten readiness" is more about self care (Can he put on his own jacket? Take his shoes on and off? Go the the bathroom independently?) If the school does circle time, it may be important for him to be able to sit fairly still for 5 or 10 minutes. And basic social skills, like being able to share without completely wigging out, or be capable of 30 seconds of "clean up" before moving to the next activity.
I have a friend whose boy Nick is 11 days younger than mine - they are both August babies, so they are always the youngest in their class. They met in the infant room at a daycare, and moved up together through each transition. Nick was always very clingy and emotional during each transition. Even now, when I babysit him, he tends to get upset over very minor setbacks and say "I want my mommy!" - I mean, he's just a little slower emotionally. In some areas, like drawing, forming letters, creating art and music, he's really impressive! But, because of the emotional thing, the teachers, principal and parents have decided to wait another year for kindergarten. And the parents are *fine* with it. (It was a little jarring at first, but they observed him closely, thought about it, considered the possibility of being held back at the second grade instead, and gradually warmed up to the idea.)
There's even another little boy at the school, he's in 3rd grade now. The kid got held back for kindergarten - again because of the emotional development thing. And at that time, that was the right decision. But a few years later,
he's always the class clown, cutting up and stuff. The parents get him tested, and it turns out the kid's a genius among geniuses. He's like those 12-year-old kids that go to Harvard - they have a PhD before they are old enough to drink beer. The school is pretty understanding, and everyone, the school, teachers, parents are scrambling to to keep him occupied and interested in school, while still keeping him with his age group.
The point is... it really shouldn't be about what they "know" or "don't know". It ought to be "what can they handle" and "are they emotionally ready".