The whole problem with considering moral and social values in a selection process, whether it's for a job or for selection in a sports team is that you only often find out what a person's values are after you've known them and worked with them for a while. From the fact that Reece hit his missus and was charged for it, you cannot infer that he thinks it's okay for a man to hit a woman, which would be a moral value that would stand in the way of selection in any rugby team. From his actions afterwards, the processes he's been through, the discussions he's had with the Crusaders' coaches, players and staff, they would get to know him and they've concluded that he's a good guy who has made a bad mistake, but who has improved and is still improving himself as a person.
If a guy thinks it's okay to hit a woman and says that publicly on a regular basis, including on his social media, or if he has been convicted for it multiple times, then you will know some of his moral values and can use that as a reason not to hire/select him. But how often does that happen? In a job interview or before signing a player, on most occasions, a candidate/player wouldn't say such things (except in case of convictions, which you can be asked for on an application form, or during a job interview). You'd generally find out later once you get to know him.
Another problem is that it is a slippery slope. Which moral and social values are we talking about? Who asseses what your values are and whether they meet those of your organisation? Some values will be reflected in certain protocols, such as those adopted by NZR after the Chiefs stripper debacle, but what about others?
NZ society has some common moral standards. Most of them are just boundaries, like those laid down in law. Others are more common sense, unless you work in certain situations like working with children or other vulnerable people. Usually these are regulated. Also working for government agencies mean you have to agree to certain standards (not sure whether you'd call them social or moral standards though).
Why isn't this enough? I don't see why they should be made explicit, only because we're dealing with rugby teams.