Ann: Appendix 4C - quarterly, page-10

Not very impressed to see redesign already happening but better to do early in production before units are sold and spares are inventoryed

From quarterly

This will coincide with a product upgrade to Terra Dura®. The introduction of a new sealing arrangement as well as the strengthening of both inner and outer polymer covers are measures to further improve durability and reliability of the brake

So are they talking water seals on claming covers of drum or bearing seals  and considering their testing I suspect they just needed product to market so they could raise  but new design changes were needed.  Failures already happened?  Redesign is a burden especially if any decertification is required.  Redoing molds etc all costs time and money.