https://wccftech.com/ios-15-will-add-and-drop-widgets-automatically-based-on-user-information/

iOS 15 and iPadOS 15 brought a boatload of new features to the iPhone and iPad. While the FaceTime and iMessage app is beefed up with SharePlay and other features, Apple made sure to bring some design variations to the platform. Moreover, iPadOS 15 introduced users with the ability to place widgets anywhere on the Home screen. This is not all, iOS 15 will gain the ability to automatically add and remove widgets to a Smart Stack.

With iOS 14, Apple introduced widgets and Smart Stack. The latter is a cluster of widgets stacked together so it takes less space and provides more information. You have the option available to stack your desired widgets together but it seems Apple is adding another layer of greatness over it. iOS 15 will display widgets based on your preferences automatically while removing the less relevant ones from the list.