Split Screen will be revamped and called App Pairs in Android 12.
In Android 12, the App Pairs system will group two apps together.
This means you could pick any two apps from recently opened apps to make a pair.

Check out the picture given below, the feature might look like this.
App Pairs in Android 12 will give a divider to let you adjust the screen space for each app.
This divider lets you quickly swap the positions of the two apps by double-tapping on the divider.

Some of the Samsungs phone has a feature with the same name, App Pairs.
App Pairs on Galaxy phones are the shortcuts to open two apps in multi-window mode.
It is expected that the first Android 12 Developer preview will be coming in February.

As same has happened for Android 11 last year, so the preview will be coming on time.
Android 12 is still under development.
