Different overloads of ObservableObject.RaisePropertyChanged (using a string or an expression) both raise the handler. As the final raise of the event is based on a string propertyname, I think it would be cool to have the "Expression" version to
call the "string" version instead of raising the handler on his own.
In the case you want to catch the RaisePropertyChanged event from a subclass, you would need to only override the string version to be sure to have all cases (name resolution from expression is already solved).
Cheers from Paris !