He said the exciting uncapped wing deserves a chance to better himself after an earlier domestic violence charge.
In October, Reece, now 22, was discharged without conviction in the Hamilton District Court on one count of male assaults female, which he admitted to.
He has since blossomed during his time in Christchurch.
He has scored 15 tries and satisfied all that he is not only comfortable in Super Rugby, but that he has potential to be the same at the next level.
Hansen and his fellow selectors believe the Fijian-born Reece has the character and quality to represent New Zealand and thrive in the high-pressure test rugby environment following his standout performances with the Crusaders in his first year of Super Rugby.
In an interview with the New Zealand Herald Hansen said Reece, one of four new caps selected in the 39-player Rugby Championship squad, wouldn't have been picked if he didn't have what it took to be an All Black on every level.
"I think it's really important to understand that no one condones domestic violence," Hansen said.
"At the same time, as employers of anyone who goes through that, you have a duty of care to help that person get better, and I think in the case of Sevie, the Crusaders have done a magnificent job of working with him.
"He has flourished in their environment - there's no doubt he's a better person, from what we can understand, and he's performing like a world-class athlete.
"As New Zealand Rugby employees, we have a duty of care to make sure we turn our rugby players into better people because better people make better All Blacks.
"Really all our job now is to bring him into our environment, as we've chosen to, and make sure he continues his growth as a human being and man and live up to all the expectations that we have for all of us in society.
"We look forward to working with him because by all accounts he's a lovely young man. Yes, he's made a mistake and he's recognised that and has improved himself because of that mistake. That's all you can ask another human being to do."
There is also a feeling within the All Black coaching group that Reece, who has re-committed to the Crusaders until 2021, wouldn't be playing as well as he has if he hadn't learned some important lessons and embarked on a fresh start. Reece's ability to consistently create opportunities for himself and his teammates with his pace and power has impressed Hansen, and the right wing could be a point of difference at the World Cup.
Asked today in a press conference in Auckland as the All Blacks continued their pre-championship camp without the Crusaders, who are preparing for Saturday's Super Rugby grand final against the Jaguares in Christchurch, how much of a bearing Reece's off-field issues had in his selection, Hansen replied: "They didn't form any, really. That's all been dealt with – both in the court and by the rugby union.
"We've had conversations with the Crusaders people who have been managing him and everyone's giving him a massive tick and he's giving himself one on the track as well as off it at the moment.
"Whilst you have to take it into consideration, it's been dealt with so we've moved on. He's playing really good football – I don't think there's one New Zealander who wouldn't put him in the team."
Neither Reece nor any of his Crusaders teammates will play in the first Rugby Championship test against Argentina in Buenos Aires on July 21, but he is a possibility to play against South Africa a week later in Wellington.
The All Blacks will leave for Buenos Aires next Friday, minus their coaches, who will remain in New Zealand for a couple of days to monitor the Crusaders and get them up to speed with the game plan for the Championship.
The World Cup is obviously the main priority, but the first big one is the retention of the Bledisloe Cup – the two tests against the Wallabies are in Perth on August 10 and in Auckland a week later.
The long and arduous Super Rugby season has appeared to have taken its toll on the Hurricanes, in particular, following last weekend's Super Rugby semifinal defeat to the Crusaders.
Neither Beauden Barrett nor Ardie Savea have made it to Auckland due to illness, with Jordie Barrett and Asafo Aumua also affected.