In Android 15 QPR1 Beta 2, a new feature was mentioned that will allow synchronizing notifications between different devices. This was reported by Android Authority.
In the settings on the notifications page, a new item "Synchronize across devices" has been added. This option allows you to remove notifications from all devices at once.
For example, if you receive a notification on both your smartphone and tablet, you only need to read it on your smartphone to make it disappear from both devices at once.
There is also a possibility that this feature will be available not only for Pixel smartphones, but also for other devices running Android 15. The new option was found under the name com.android.settings, but the Pixel-exclusive features can be found under the name com.google.android.settings.
It will probably be possible to set up notification synchronization via Google Play Services, similar to the Instant Hotspot feature, which allows you to add devices that will automatically connect to another smartphone or tablet's network.
So far, Google has not made any announcements about such an update, but since the feature has already been mentioned in the beta of the operating system, it is possible that its official announcement and release will take place soon.