There were several consultations held. In his report following the 2015 general election, the Chief Electoral Officer recommended that the special voting rules applicable to Canadian Forces members be reviewed given their age. This committee accepted this recommendation in principle, so there were consultations between Elections Canada and the Canadian Forces for about six months, which led the Chief Electoral Officer to table supplementary recommendations before this committee in June 2017. Following June 2017, the Canadian Forces have been collaborating with the Government of Canada to make sure the amendments included in Bill C-76 would be reflecting concerns of flexibility, but also operational security, for example.
On May 28th, 2018. See this statement in context.