I've tried looking for information about this method and I'm unable to understand what's the meaning and utility of it.
This is what MSDN says about it: https://msdn.microsoft.com/en-us//library/vstudio/system.xaml.xamltype.getaliasedproperty(v=vs.100).aspx
What does it do, in other words? Are examples available?
You could imagine, buttonXamlType.GetAliasedProperty(XamlLanguage.Name) would return a XamlMember for FrameworkElement.Name. This means that x:Name and Name, when used on a button, are aliased, or synonymous. Defined by [RuntimeNamePropertyAttribute("Name")] decoration on FrameworkElement class.
Asking buttonXamlType.GetAliasedProperty(XamlLanguage.Lang) would return a XamlMember for FrameworkElement.Language, as the [XmlLangProperty("Language")] attribute is on the FrameworkElement class.
-Rob Relyea, PM/Architect for System.Xaml.dll