Which language used in countries without localization? (primary language or English?)

Hello,

My app is available in various languages that I have added as localizations to my app's meta data and the app itself. Unfortunately I set the primary language in App Store Connect to German and not to English.

Two questions:

1: I'm wondering in which language the App Store meta data will be displayed in countries for which I haven't added a localization in App Store connect? Will it be English or the primary language (German in this case)?

Example:

-App Store description and screenshots are available in the following localizations: English, German, French, Spanish

-App's primary language in App Store Connect: German

Question:

In which language will people in e.g. Poland who have set their iPhone to Polish language see my app? There is no localization for Polish available. There is an English localization available but the primary language in App Store Connect is set to German. Will people in Poland in this example see my app in the Polish App Store in German or English localization?

2: When I now change the primary language of an app in App Store Connect from German to English does this have any consequences? Can I do that without being afraid of loosing meta data like screenshots, description, keywords etc.? I don't have to add all this new for all languages, do I? Do I have to pay attention to anything else?

Thank you so much for your help!