As a German that's the first time I hear that. Do you mean Schülerpraktikum? That's usually at age 14. Never heard anyone doing that at age 9.
Where are you in DE, that this is unknown to you? In Köln just 15 years ago I knew parents who had the horror scenario: a 4th grade teacher who quietly believed that girls shouldn't go to university. They switched their daughter schools that year.
I also know enough people who did perfectly fine via Realschule to academics. Of course it's a decision with pretty much a single point of failure which is suboptimal, but don't act like it's predetermining your whole carrer.