The metaclass DataType was already introduced in Abstractions. But in Constructs, the genealogy is changed significant.
In Abstractions, DataType was a direct child of Type. In Constructs, the Classifier is inserted in this generalization relationship (as specialization of Type and as generalization of DataType).
Looking at the inheritance tree, I also note that DataType isn't descending from MultiplicityElement.
As written before, DataType also differs from the class in respect that it doesn't have an identity. This is actually the behavior of a native LabVIEW object.