I'm a nurse and I can say that Goodell's sign used to be very important when other methods of confirming pregnancy were not available like the article said.
But now, physical signs like Goodell's sign and Chadwick's sign are not considered positive signs of pregnancy. So no practitioner will confirm a pregnancy simply looking at these signs. Ultrasound and urine test are preferred methods now.
These signs are still looked for by nurses and other caregivers, but simply to see if there is a probability of pregnancy. If they are present, further testing will be done to confirm or deny a pregnancy.