Is it a rescue? Maybe. Is it a rescue mission? No. It's a normal crew rotation mission that has happened to (arguably) rescue a few people on the way. The mission itself is ordinary, expected, and planned prior to any crisis.

Arguable because everyone has a way back already, the modification to the crew rotation mission just provides a somewhat safer way back.

Edit: And the distinction here matters. A rescue mission would be an expensive unexpected endeavour. The regular crew rotation is an expected operating cost. The modification to the details of the plan for the crew rotation haven't significantly impacted the mission goals - i.e. for the same cost there are still the same number of fresh qualified crew members up there for the same duration, just a slightly different set of people.