At the moment {xen: property name} exposes the certain property to a complete format: @property "name"; properties @property "/name"; after a template save. I think that the correct behaviour should be like this: Template contains only {xen: property 'name'} but the final result (the one we get via css.php) is a property content.
The actual behavior is: Template editor exposes entire property marked up. Changes within that only change the property, not the the template. The template only contains {xenroperty name} and the final output is the property content. So, no bug here.
I thought that it should just include a property, not to expose it, because we can already do it with @property "name";