Having flown the Airbus 320/321 for more than 11 years, total brake failure is not a new thing, sorry to say that !
Some years ago the "Brake dual shuttle valve" was blamed. A new was introduced.
Brake failures still occur, and brake failure procedures are a major subject on each OPC now = Antiskid/NWS SW OFF - alternate braking. Last resort = park brake ON
Interesting to hear what the problem was this time. My guess is that the crew will be blamed for not dealing with a faulty system in a proper way. Where actually Airbus is to be blamed for having designed a "bad" brake system.
Well I should not speculate about this, but wait for the report........