With Android 11 Developer Preview 3, Google has added a new toggle for app permissions named “Auto revoke permissions”. As the name hints, the feature will automatically remove permissions if an app is “not used for a few months” and it is disabled by default.
It is worth noting that the feature doesn’t revoke all the permissions granted to an app. There are certain “auto revocable permissions” that respect this toggle and it varies based on the app.
However, an option to set a custom time-frame would be much appreciated. Android Police notes that the list of revocable permissions change when checked at different time intervals, which could be because the feature is at its early stages and it explains why Google has hidden it by default on this release.