Map is outdated. How to update

Map data is requested online when it is needed, it is not in the app itself. Updated maps and updates of the app are separate. The map you get to see, is what is available through this app at this time. TomTom (where Apple gets it maps from) releases about four map updates per year for themselves, which is likely the same as what Apple gets access to.

If you are inclined to help out, in Maps.app on the iPhone, you may click the ℹ, then Report an Issue, Other Issue, then make a description of e.g. the missing streets and the GPS coordinates of that area, and optionally add a photo.

Maps are generally updated when you get an iOS update (it's a built-in app).

But if you have to notify something new, contact Apple using this form:

Feedback - Maps for iOS - Apple

Regards

Giulio