What the new Motu Proprio really means

My editor Luke Coppen has flagged up a new Motu Proprio coming out of Rome which heralds some changes to Canon Law. Motu Proprio Omnium in mentem looks like it is mainly revising laws that have to do with people formally leaving the Church and getting married. It looks like it might be a generous revision. I asked a canon lawyer what it meant. Here is the reply: