Is MonoTouch.Foundation.Preserve still necessary for entities?

It used to be that you had to decorate pure entity classes with MonoTouch.Foundation.Preserve otherwise the compiler could think that a property wasn't used, especially if you just did basic serialization. Is this still necessary?

[MonoTouch.Foundation.Preserve(AllMembers = true)]
public class Foo
{
    // ... properties and such
}

JB