In de Last week, Apple announced new guidelines for the App Store. These prevent apps from cryptomining and finally give developers the opportunity to offer paid apps as trial versions. According to Bloomberg, Apple has also made changes elsewhere to improve privacy. The new guidelines in Section 5.1.2 are designed to prevent app developers from obtaining user data from contacts, photos, or other APIs to create a targeted user profile for potential advertising. At the same time, it aims to prevent contact data from being used to build up extensive contact databases that can be used to contact users without the installed app.
Compared to Bloomberg a developer said that the data were previously easily accessible and could be collected easily without Apple's knowledge. Among other things, he stated that it is very easy to transfer all contact data to another server or to upload it to Dropbox, for example. This can happen at the exact moment a user gives his "okay" for contact access. According to the developer, Apple should not check this and also do not know where the data has been sent.
You can read the full App Store guidelines on Apple's website. However, these are only available in English.