So are you also not allowed to move away or? I find it pretty messed up that your life as a man is literally owned by the government.
The consequence is you violated the law, and they can have you at any time, even retroactively, for that.
That they don't is merely a detail. If it really has "no consequence" they should remove it.
And no, Germany does not allow retroactive criminal punishments. That’s more something that happens in Russia, China and probably soon America
I think it's clear that the interests of citizens and their state typically do not align. Unfortunately, most states have cultivated and propagated a different idea for decades, which is why so many people have a different perception of their state than the reality.
Instead, my 2c, should have changed it to a notice you have to send the military, at most.