I just talked to someone on the govt's Coronavirus info line and he stated that extended family members will have to reapply every time they want to visit Canada. This seems unnecessarily cumbersome but I assume the goal is to discourage visits. If anyone knows anything different please share. Thanks
Yes, this appears to be correct (i.e. need to reapply each time).
Yes, this is to discourage visits during the pandemic. People should only be traveling for essential reasons. Canada wants to limit non-essential travel as much as possible and the reasons for an individual's travel have to be evaluated each time.
Numbers are going up in many places across the world, including Canada. So this is a pretty logical measure.