How can we subscribe to the window events?

[ClaudiuHBann]

After the RNW 0.78.0 version, I think, the basic WinUI3 App class which had OnLaunch event got changed into a win32 style window app.
I can see that there are a few events Changed, Closing and Destroying (AppWindow)
Are there events like OnLaunched ? If yes, where are located and how to use them?