Originally announced at WWDC this past summer, Apple has been scant on details of the pending timeline Apps will need to follow in order to comply with the new developer guidelines.
Apple began to pull back the curtain on November 5th when they released the following statement and explainer:
On each app’s product page, users can learn about some of the data types the app may collect, and whether that data is linked to them or used to track them. You’ll need to provide information about your app’s privacy practices, including the practices of third-party partners whose code you integrate into your app, in App Store Connect. This information will be required to submit new apps and app updates to the App Store starting December 8, 2020.
https://developer.apple.com/app-store/app-privacy-details/
This gives App owners just over 30 days to collect, analyze and sort the data their Apps and 3rd Party SDKs collect so that they can continue to submit Apps and App updates to the AppStore past December 8th 2020. The previously announced prompting of permission has been delayed till early 2021 (no date given).