He extended his contract in early 2017 through to 2019 but that would be it he said – he wouldn't be entering negotiations before the tournament in Japan.
But as much as it has appeared to be a fait accompli, Hansen has never quite shut the door on the prospect of staying on.
There have also been a number of significant statements made in the past that have to be considered in plotting the map of the future.
The day after the All Blacks won the 2015 World Cup Hansen announced he was 90 per cent certain he'd be moving on after the Lions tour in 2017.
Perhaps that was a negotiating ploy to go public about his probable exit at a time when his star could not have been shining brighter, but then he had argued consistently that the All Blacks coach should not be contracted in sync with World Cup cycles.
His belief is that the World Cup should not be the ultimate and in essence only means of evaluating a coaching tenure and that change should come mid-cycle.
It's a battle he has won as NZR have told him, it is believed, that there is a two-year extension on the table if he wants it to take him through to 2021 – presumably with the intention of handing over control two years before the 2023 World Cup.
So the picture now remains as conflicted and as unpredictable as it has since the day after the last World Cup final, to everyone that is accept Hansen.
He said after the All Blacks last match this year against Italy in Rome that he has been sure of his plan for months.
That in itself provides no clue about his intention and nor does the announcement by Ireland coach Joe Schmidt that he will be retiring from coaching after the World Cup.
This is a mystery without clues as such, more logical denouncements that tend to support the theory that Hansen will be standing down this time next year.
The job takes an enormous toll – has an all-consuming quality about it which is tolerable, but not forever.
The intense media scrutiny Hansen can withstand, making it clear in Rome that he won't be bullied into selections or strategies that are not his.
The pressure of the big games he still loves. The match day tension, the uncertainty and excitement of it all, the chance to see the hard work come together still gets the adrenaline pumping and his competitive juices flowing.
But the amount of work that has to go into get to that point is draining and relentless and it comes at the expense of normality.
The sacrifice is huge. It is not just the days, weeks, months away from home and parenting via Skype. It is not just the endless phone calls and meetings – the need to constantly be across what is happening in the lives of his players and management team.
It is the totality of it all – the feeling of being owned and in demand from everyone else.
Hansen has talked before about how he has come to accept he is public property – revealing that while he would like to take a casual stroll with his wife without interruption, he knows it won't happen.
He revealed in the Amazon Prime documentary just how intrusive people can be and that he has to draw the curtains during the day to stop on-lookers gawping at him in his house.
The job has hidden demands and having been head coach for eight years and with the All Blacks since 2004, if Hansen wants his life back then it wouldn't be before time.
Which brings into focus the long-swirling rumour – it dates back to the start of this year - he's set to take a new role in 2020 as director of rugby.
On one level this stacks up as credible. He could assume in this new role, some of the responsibilities of his current post.
He talked, enviously, after the defeat to Ireland about their dictatorial system of ordering players to rest from club games and the benefit that comes with it. He made it clear he felt New Zealand needs to do the same.
As director of rugby he could be the fulcrum between Super Rugby clubs, the All Blacks and NZR – preside over a more universal system of player management. He could be more involved in player contracting, talent identification and coach mentoring.
It all makes sense but for the fact that Hansen would be handing over the parts of his current role that he loves to someone else while he picked up the jobs that he hasn't given the impression to date quite light his fire in the same way.
There's a suspicion he'd love for there to be a director of rugby to free him up to focus more on the pure art of selecting and coaching so as much as it is easy to believe the rumour mill is right, it is just as easy to dismiss it.
Hence we await his news none the wiser yet skewed to anticipating confirmation he's standing down.
What ultimately tips the balance that way is the intangible sense that the time is right.
Those who don't know much but feel that they need to show they do, say that a changing room gets sick of hearing the same voice.
A changing room switches off to a repeat dose of the same ideas, not the same voice, and coaches are no different to doctors, lawyers or chefs in that if they continue to evolve, their career can run indefinitely.
Hansen has evolved and hence the All Blacks have too on his watch so the feeling of this being the right time to move on is not driven by fears of him being stale.
It's driven by him being part of something bigger than himself and the belief that the whole New Zealand rugby ecosystem needs to periodically refresh itself.
Regeneration is nature's way of keeping its most precious resources strong – there is a natural cycle of life.
And if nothing else, Hansen has had a great run. A brilliant run that will be tainted but not dented by an unsuccessful World Cup campaign next year.
Few coaches get to leave a job on their terms, with their legacy secure and for a man whose reign has been defined by the phrase risk and reward. The former would heavily outweigh the latter if he chooses to stay past the World Cup.
