"To be fair I think they need to lose," he told New Zealand's Radio Sport, saying he saw similarities to 2007 when the All Blacks crashed out of the World Cup at the quarter-finals.
Henry coached the All Blacks to the 2011 World Cup after they lost their last two games going into the tournament.
He was also at the helm in 2007, when they went into the championship with a rich vein of form similar to the current side.
As the top-ranked team on the planet the All Blacks are expected to win every game and the World Cup and "the reality is that's hugely difficult", said Henry, speaking a year to the day before hosts England play Fiji at Twickenham in the opening match of the next World Cup.
"The odd hiccup here and there gives you the opportunity to re-analyse where you are at, look at everything, turn over every stone, make sure you're on the right track. If you don't do that you might miss something," he added.
The 2007 World Cup side lost only three times in the 32 Tests they played leading into the tournament where, after an easy round of pool matches, they were beaten by France in their first knockout game.
The current All Blacks have not been beaten in their last 21 outings and have lost only once in 35 Tests since they beat France 8-7 in the 2011 final.
Henry said a loss before going to England next year might do them good.
"I think (a loss) galvanises people, it makes them re-analyse where they're at and make sure they're on the button," he explained.
"Because I think there's some similarities to 2007 here."
The All Blacks play Argentina, Tonga, Georgia and Namibia in pool matches next year and if they top their group as expected they will likely face Ireland, France or Italy in the quarter-finals.
Along with the All Blacks, Henry rates England, South Africa, Ireland and Australia as 2015 title contenders.
I dont neccessarily agree with Henry. This ab side is different, they have very high expectations and standards. I dont neccessarily agree that a team needs to lose before you can wins. Or see a teams faults. You can do that while winning. Abs hv already hd some close games, games you well see at the wc, but they just find a way to win. Same accord teams who win wcs, are only good for that three week periord. Then suck for 4 years so whats the point of difference. Nz are consistently the best side in the world, for four years leading to the wc and afterawards, regardless of NZ performance at those select Wcs. To me thats more important. Seems everyone puts so much emphasis on the RWC, but its not neccessarily the be end and end all imo. Opposed to that 2007 side Nz has matured and evolved, and has actually closed out close pragmatic games like 8-7 final, Eng games, 14-10 over SA last weekend etc.
