The XAML team has recently reviewed this feature request and will not be addressing it as at this time. Feel free to use the OnDropDownClosed event to check which is the selected item. If this feature is critical for you or there is some other use case, where OnDropDownClosed is not applicable, please contact us through the support ticketing system with details on your setup and a reference to this item.

The event similar to SelectionChanged, but it should be raised only when user selects the item(click, enter, tab) and it should not be raised when due to filtering item is selected.