Would there be any will to change TestContext to remove reference to a Method and use something like array of Annotations or Description instead?
No, a change of this magnitude would not be possible since it would break backwards compatibility.
Furthermore, JUnit's Description appears to be too limited for our purposes. Similarly, relying on JUnit to provide Spring with the annotations we need (e.g., via an array of annotations) would never be acceptable: Spring has very different goals with regard to the annotation and meta-annotation programming model that we provide users of Spring. Thus Spring must always be in control of the annotation and meta-annotation look-up algorithms. See AnnotationUtils, AnnotatedElementUtils, and MetaAnnotationUtils for primary examples.