This is the article for a quite a while. But I do have some further query maybe you can help to understand.
In order for a foreign national to be eligible under this exemption, there must be 2 or more foreign nationals who are immediate family members of each other, and authorizing one or more of them to enter Canada must allow them to be reunited.
While the foreign national’s immediate family member must be a resident in Canada, that family member does not have to be a Canadian citizen or permanent resident.
This means that a foreign national with an immediate family member temporarily residing in Canada as a worker, visitor, student or protected person, would be exempt under this provision if provided with written authorization.
An adult child of a person residing in Canada may be eligible under this exemption. This is because, while the child is not an immediate family member of the parent under the definition above, the parent is an immediate family member of the child.
Written authorization may be issued to facilitate family unity at the onset and allow for the whole family to travel together and establish residence in Canada. There is no requirement for the head of family (ex. a worker or student) to come to Canada first and the rest of the family travel at a later date with authorization letters to reunite in Canada.
Accompanying family members may be issued written authorization under this family reunification provision if they are not otherwise exempt under another exemption. However, their travel must still be non-optional and non-discretionary. Generally those accompanying family members seeking to establish themselves in Canada will be considered to be travelling for a non-discretionary purpose.
The highlighted part is quite tricky to understand. If a first-time temporary foreign workers is to enter Canada together with his family does IRCC or Border officers immediately consider him a resident of Canada that makes him valid?