Certainly it's understood, in that case, that the requirement with respect to existing accounts in place on July 1, 2017, when it's proposed the system will come into place, is that institutions can rely on the address they have on file for a person. The requirement is essentially that they identify any non-residents they have on file. If there are very few, one might expect that it will not be such an onerous exercise. They're not required to contact people. They're entitled to rely on their paper records, or I guess, in cases today, on electronic records.
On November 17th, 2016. See this statement in context.