Why SelectionChanged is called when view is unload

问题:

Below is an mcve (to reproduce the problem it has to be datatemplated unloadable view).

xaml:

<Window Content="{Binding}" ... >
    <Window.Resources>
        <DataTemplate DataType="{x:Type local:ViewModel}">
            <ListView ItemsSource="{Binding Items}"
                      SelectionChanged="ListView_SelectionChanged"
                      Unloaded="ListView_Unloaded"
                      MouseRightButtonDown="ListView_MouseRightButtonDown">
            </ListView>
        </DataTemplate>
    </Window.Resources>
</Window>

cs:

public class ViewModel
{
    public ObservableCollection<string> Items { get; set; } = new ObservableCollection<string>(new[] { "1", "2", "3" });
}

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext = new ViewModel();
    }

    void ListView_SelectionChanged(object sender, SelectionChangedEventArgs e) => Title += "S";

    void ListView_Unloaded(object sender, RoutedEventArgs e) => Title += "U";

    void ListView_MouseRightButtonDown(object sender, MouseButtonEventArgs e) => DataContext = null;
}

Start program, select item in the list ("S" will be added to title), right click inside list -> "SU" will be added to title.

Question: why SelectionChanged is called when view (ListView) is unloaded??

Right-clicking without selecting anything will add only "U" to the tittle.

Simply closing software (disregarding selection) will not cause SelectionChanged (tested by setting breakpoint).

I will have some logic in SelectionChanged event and I don't want it to run when view is unloaded, it's unexpected behavior what SelectionChanged event is called in this case at all.