Yes things do change and typically for the better. As Deb noted, stunning is no longer considered appropriate. In addition to not stunning rodents, there have been other changes in the last 20 years:
Myth: Feeding snakes in the enclosure will cause the snake to become aggressive and mistake your hand for food, so it should be moved to a separate tub for meals.
Fact: You are more likely to get bit by a hungry snake if you attempt to move it than if you just feed it in the enclosure, and you can tap train a snake to break its food response so it doesn't mistake your hand for food when it's not time to eat.
Myth: Freezing a snake is a humane method of euthanasia.
Fact: While the snake's body goes torpid its brain remains active, so it feels itself painfully freezing to death. Freezing is not humane. Pith the brain if you need to put a snake down quickly, humanely, and painlessly.