While obviously technically Nominatim could be expanded to extrapolate locations for addresses that are not contained in the database. Given that doesn't mean that such addresses actually exist, it is probably outside the current design goals of Nominatim (you can naturally write such an extension yourself and make it available). Note wrt "found online": As mtmail noted, the above applies to my knowledge there is no country wide open data not explicitly mapped interpolations (there we assume that everything between start and end address dataset available for Germany, so likely that data is not only not suitable for OSM use, it likely has been illegally obtained in a more general sense of exists using the words. resp. interval).

While obviously technically Nominatim could be expanded to extrapolate locations for addresses that are not contained in the database. Given that doesn't mean that such addresses actually exist, it is probably outside the current design goals of Nominatim (you can naturally write such an extension yourself and make it available). Note wrt "found online": to my knowledge there is no country wide open data address dataset available for Germany, so likely that data is not only not suitable for OSM use, it is likely has been illegally obtained in a more general sense of the words.

While obviously technically Nominatim could be expanded to extrapolate locations for addresses that are not contained in the database. Given that doesn't mean that such addresses actually exist, it is probably outside the current design goals of Nominatim (you can naturally write such an extension yourself and make it available). Note wrt "found online": to my knowledge there is no country wide open data address dataset available for Germany, so likely that data is not only not suitable for OSM use, it is likely has been illegally obtained in a more general sense of the words.