The Canadian sevens coach departs June 22, one day after his daughter's high school graduation, for Sydney and his new job as head of Australia's sevens program.
"It is a massive loss for Canadian rugby," said Canadian head coach Kieran Crowley.
Also for Crowley, who will see a good friend and colleague move to the other side of the globe.
The two have worked side by side — with John serving as an assistant coach of Crowley's 15-man team and Crowley as an assistant coach on John's seven-man squad.
Crowley, a former New Zealand All Black, will do double duty as sevens coach through the Commonwealth Games, which run July 23 to Aug. 3.
Ben Herring, Rugby Canada's technical coach and performance analyst, will take on more sevens duties in the short-term. Herring, a former pro in New Zealand and England, was with the sevens teams for two events this year and the players lauded his defensive coaching skills.
The goal is to have a new coach in place the end of August.
Unlike the 15-man game with its pro leagues, the sevens world is small.
"We'll have to look hard," Mike Chu, Rugby Canada's general manager of rugby operations and performance, said of the coaching search.
The good news is that John, a 51-year-old native of Wales, leaves the sevens program on all-time high. Once struggling to win back status as a core team on the IRB World Series, Canada finished sixth on the circuit this season and made a final, in Scotland, for the first time.
That, combined with his experience building the Canadians program, made John an attractive catch for Australia, which finished fifth on the circuit this year.
The Wallabies are ranked third in the world — compared to No. 15 for Canada — when it comes to 15-man rugby. But like many top-tier countries, their 15-man and seven-man programs have been largely separate.
Canada's two programs are far more integrated, with many players taking part in both.
Without a domestic pro league, Rugby Canada has been able to hone players on the sevens circuit. Plus the added funding coming from sevens joining the Olympic program in 2016 has allowed Rugby Canada to improve the support network for its players.
Canada's sevens players have been centralized for two years and now work out of Rugby Canada's centre for excellence in Langford, B.C. The Australian Rugby Union just centralized its sevens program this year in Sydney.
The ultimate goal is to open a pipeline into the rich vein of talent available in Australia's Super Rugby teams, with an eye to fielding the strongest possible sevens squad for the 2016 Olympics.
Australia's 15- and seven-man players are currently under separate contracts with the Australian Rugby Union, although John points to a player like fly half Bernard Foley of the New South Wales Waratahs as someone who caught the eye of the Wallabies though his sevens play.
Foley won a silver medal with the Australian sevens team at the 2010 Commonwealth Games and went on to serve as team captain in the 2010-11 IRB Sevens season.
John's hope is to establish the kind of centralized program that will win the support of Super Rugby.
"We have to make sure that if those players do come into a sevens program that they are being looked after not just as well (as the Super Rugby teams) but ... a little bit better than that," he said.
John's mouth must water when he sees the talent that could be available to him.
Wallabies fullback Israel Folau, a member of the Waratahs who is reportedly being targeted by European champion Toulon, would be just one of the bumper catches. Now a star in rugby union, Folau has also excelled in rugby league and Australian Rules Football.
"You look at him and say 'Wow what a phenomenal sevens player that guy could be,'" said John. "But at the moment, he's New South Wales, he's a Wallaby. He plays for the 15s, he's got World Cup next year. You know he's fully committed to that program.
"What may happen after 2015 and the World Cup, we don't know. .. But he would have get involved in the sevens program and supported in the sevens program and train within the sevens program before playing the game, because they are slightly different games. They do need a certain amount of time.
"I think it's very very difficult, or virtually impossible just to go from one game to the other these days. The game has changed dramatically but (having Super Rugby players involved) is an exciting prospect and they're looking towards it."
John, whose playing career included international honours with Wales A, Wales B and the Barbarians, moved into coaching in 1992 and spent six years as an assistant coach with Cardiff RFC and Cardiff Blues. He was skills coach under New Zealand's Graham Henry with Wales from 1999 to 2001 and also coached the Welsh sevens team.
He joined Rugby Canada in 2006 as high-performance director and became coach of the sevens team in 2010.
Rugby Canada tried to keep John with a counter-offer, but the decision was made.
"We're very disappointed not to keep him. But by the same token we wish him all the best in his new challenge," said Chu. "He's been a fantastic servant of Rugby Canada for nine years now."
Chu calls John a players' coach with strong ties to both his staff and team.
"The players love him and they really play hard for him," he said. "He's a good student of the game ... A terrific leader, a terrific coach.
"The big thing for me is he's a hell of a good person. Great work ethic and very passionate and it comes through in everything he does. So not only are we losing a terrific coach but we're also losing a great guy to have around the place. A terrific person. He'll leave a massive gap for us just as a quality staff member, let alone his coaching."
Under John, the sevens team made a point of taking time to smell the roses on tour, whether it be putting on a clinic for local youth or visiting the world's tallest building in Dubai.
John came over to Canada in 2000 with a Welsh development side, stopping in Newfoundland, Ontario, Alberta and B.C. He liked what he saw.
"I just found everybody was so friendly. There's a passion for rugby within the country. The people were great," he recalled. "I just loved the country."
When the opportunity came to join Rugby Canada, he got his chance to put down roots here.
He and his wife thought they would never leave. But the Australian offer came at a good time, with his daughter about to graduate.
"At this moment in time, it probably fits in," he said. "Any other moment in time, it probably would not have."
The lure of a well-funded program looking to better tap its rich resources was too much. Plus he gets to run the entire Australian sevens program, with the women's side also falling in his domain although he will be most hands-on coaching the men.
He will be on his own to start with, with his wife electing to say on in Canada a little longer to ease the transition at Shawnigan Lake School where she is a house director.
But John will have company. His daughter, who is taking a year of before going to university, plans to visit him in August. His stepson is also likely to visit from the United Kingdom.
And he will be busy, with the Commonwealth Games fast approaching and then the October start of the IRB World Series at the Gold Coast Sevens. It's a crucial season with the top four teams earning Olympic qualification.
John succeeds Michael O'Connor, who stepped down in February after six years as Australia's sevens coach.
The Wallabies finished runner-up at the Gold Coast and London events this season. Canada and Australia met on the circuit, with the Australians winning 12-10 in New Zealand and 14-12 in Hong Kong.
While John will be missed, fly half Harry Jones believes the close-knit nature of the sevens squad will endure.
"All the boys have all the faith and trust in him," he said of Crowley.