Well, no. Yes. Kind of.
No, the rules haven't changed. Yes, you can go three years between vaccinations if your vet thinks that's a good option for you. But ...
The "but" is the important part. There's a difference between the one-year vaccine and the three-year vaccine. So if your dog had the one-year vaccine last time, you haven't magically gained two years of not having to visit the vet. Your dog will need that three-year vaccine. If you got the three-year vaccine this year, you still need to get that yearly license for the two subsequent years, which you can do when you take your dog to her yearly check-up, which she will still need.
Hager said that there are a couple of other circumstances in which your dog will have to have shots more frequently than once every three years. If this is the first time your dog has gotten a rabies shot (i.e., it's a puppy or a shelter dog with an uncertain history), it will need another shot the next year before you can switch to the three year. And if your dog has been in some kind of altercation, it should have a rabies shot after that.
Last year in Tennessee, all kinds of animals tested positive for rabies — dogs, cats, bats, horses, pigs, raccoons, fox — but by far the most common were skunks. Whether this is because people tend to call for help when a skunk invades their garage, so the authorities are just seeing more of them, or if it's because skunks are more rabid in general I'm not sure. But the point is, small animals your dog might be curious about do carry rabies, so vaccinating your dog is important.
So yes, the rumors are kind of true. But you need to get that three-year vaccine and you still need to get a new tag every year.