In some cases, like Google Chrome, this splash screen is brand new in Android 12 and not a part of the app itself. In others, the splash screen gets redesigned, which is what we see with Slack.

When any app opens in Android 12, the user will see a new app launch animation, "a splash screen showing the app icon, and a transition to the app itself." This will be standard and by-default for ...

Chrome Beta 47 Can Show Splash Screens For Web Apps Launched From The Home Screen, Display A Snackbar When Downloads Are Complete, And More By Bertel King, Jr. Published Oct 22, 2015 ...