Last time I checked, all my friend's GTX 970s work perfectly fine. People looked at benchmarks, looked at performance ratings at the resolutions and settings they would be running, looked at the prices, and bought them, and they performed exactly as expected.
So, no. Its not like 6 months later they are breaking, they are still performing just the same they did when purchased, and the review copies that benchmarkers got, are the same that people purchased.
So, my vote goes for no, people don't need their money back and nvidia doesnt need to recall the cards.
Not saying they shouldnt, just that they dont NEED too.