The defections follow reports of a fractured squad struggling to deal with the fallout associated with the departure of Hager. In May, sources told the Herald the situation within the team was "faulty" and that some members of the squad and management team were actively working against changes that current coach Graham Shaw had been trying to implement, with many remaining loyal to Hager.
Now, Glynn has joined Hager in the Great Britain set-up.
"The role is an amazing opportunity for me to work with world-class athletes and staff that have been successful on the world stage," Glynn said after joining Great Britain. "I have enjoyed coaching against the squad and have always admired the way they play the game. It is a great privilege to join the group and I am really looking forward to adding what I can to continue to progress the squad."
Hager sang Glynn's praises as a coach.
"I'm delighted to have Katie on board, and she will bring the attacking flavour that we're looking for. Over the last 18 months with New Zealand she has shown an ability to help develop quality goalscorers and to create and maximise attacking opportunities.
"I'm looking forward to working alongside her as a coach for the first time, I've admired what she's done as a coach at both youth and senior level. Her personality will allow her to develop strong relationships, while challenging all to aspire to the high levels required at international level, and I know the staff and players are looking forward to working with her on the journey ahead."
The Weekend Herald first reported that issues within the camp stemmed from the findings of the Dew report, commissioned shortly before Hager's departure in January last year, which pointed to a "negative" environment.
The review was launched months earlier after Hager, a former Australian international, accidentally sent an email to the entire team, naming and shaming individual players for their performance and effort, after finishing 11th at the women's World Cup.
Three months earlier, they had won gold at the Commonwealth Games.
While Hockey NZ have denied the player departures were linked to any issues highlighted in these reports, High Performance Sport New Zealand confirmed to the Herald in May there were "ongoing issues within the high-performance set-up" but stopped short of saying whether they had demanded personnel changes.