I last taught 4th grade, and I'll tell you that getting a study guide is totally normal! However, you are right it is supposed to be the FOUNDATION for the studying of past homework, projects and of course readings.
The trap that a lot of teachers fall into is allowing this to become the only means of support they offer their students. It's really a flaw of how the school systems function, and the expectations that our system places on kids. A lot of the focus today falls on making sure OUR students PASS and not necessarily retain ALL the information.
Yes, study skills SHOULD be taught to your kids beginning in 3rd grade...is it happening?? Who knows, it's really up to each teacher and how they structure their class and manage to get ALL the curriculim into one day.
IF you are concerned about the lack of study skills or that your girls don't recall that being a part of their lesson, I would bring it up to the teachers. It doesn't have to be an attack or brutal confrontation, but a gentle 'Hey, I'm just curious how you do this?' type of approach. Most teachers welcome the questions and concerns of parents, as SO many of have NO clue what parents look like until OPEN HOUSE.
When I taught Computer Skills to 3-6 graders, I made sure to send home a weekly overview to my parents of what they would be doing, their homework and how the parents could help at home. Most of them LOVED it and made extra efforts to e-mail me and ask questions, so they could learn too.
I hope you can find a way to integrate study skills now, I think Middle School is late for learning it, but sometimes that's the first introduction kids have to learning note taking and studying.
Best of luck!
Deanna