As far as I know, yes (although I don't live in Germany) but with disclaimer that it possibly allows old buildings to stay with the ventilation they were build

As far as I know, yes (although I don't live in Germany) but with disclaimer that it possibly allows old buildings to stay with the ventilation they were build with (which used to have decent ventilation via fairly poorly airtight doors and windows). It doesn't matter whether it's active (and by active you mean having ventilation hole in the room or fan?) or not – it should provide necessary exchange anyways. Maybe it's not true for the old buildings that weren't updated but in that case they are not healthy to stay in – whether with or without line drying.