I'm not sure this is 100 percent true. I believe the 'Shu' is important beyond Shodan, certainly in Karate, because basically you are learning new kata up to 5th Dan or beyond. 'Ha' is to diverge, not break away. At this stage the kata is still recognisable but the practitioner has the ability to vary it to suit their particular needs.I think that we as Martial Artists should grow, evolve, be pragmatic, and be creative. I think that we should have that freedom instead of following the rigid, dogmatic why and worry about copying what the teacher do. This the Shuhari concept. Shu - means to copy Ha - means to break away and Ri - means to abandon and make your art your own. I say from white belt to green belt you are in the Shu process, from Green to brown you are in the Ha process and at Black Belt you are in the Ri stage where you can let your creativity manifest.
These days or it has been going on for many years, traditional dojos can act too much of a dictatorship like "you must do what I do." How can a student grow and be creative? That is telling students what to think instead of how to think. We need to be pragmatic more than just looking at only historical and only copy what the past masters did.
'Ri' is the advanced level where the technique as such can be performed without thought and may not be even recognisable as being that kata. I have only seen a handful of people training at this level.
Most Martial Artists never get beyond 'Shu'. This is because they are training the kata for competition and trying to get it technically perfect. It is only when you start to understand the application of the kata that 'Ha' becomes possible. If you are stuck in a rigid system like we were, you are not even given the option of exploring the kata.
An excellent article on Shuhari can be found at
http://www.shinyokai.com/Essays_TeachingShuHaRi.htm