final Session s = openSession();
		s.getTransaction().begin();
		
		final Project project = new Project();
		project.setName( "fooName" );
		project.setType( "fooType" );
		s.persist( project );
		
		s.getTransaction().commit();
		s.clear();
		
		for (int i = 0; i < 5; i++) {
			s.getTransaction().begin();
			
			project.setName( "fooName" + i );
			s.update( project );
			
			s.getTransaction().commit();
			s.clear();
		}
		
		s.close();

	...

	public List getProjectRevisions(String property) {
		final Session s = openSession();
		final AuditReader ar = AuditReaderFactory.get( s );
		return ar.createQuery()
			    .forRevisionsOfEntity(Project.class, false, true)
			    .add(AuditEntity.property(property).hasChanged())
			    .getResultList();
	}

...

demo.getProjectRevisions( "type" );

That will return all revisions, including the last 5 that solely updated the #name property. Calling Session#refresh prior to the Session#update is a workaround, as well as not clearing the Session after the add and each update. The issue appears to be limited to detached entities.

After discussing with Adam Warski & Lukasz Antoniak, Lukasz suggested:

I had a closer look at the issue. The root cause is that Brett updates detached entities. In SinglePropertyMapper#mapModifiedFlagsToMapFromEntity(SessionImplementor, Map, Object, Object) we do not know the previous state of the entity. We would need to introduce pre-update listener and query database (if needed) to cache original state of the entity. Of course, the issue applies only to "modified flag" feature.