As the mom of 3 reflux babies, I can tell you this is absolutely "standard" advice. Reflux babies do need to be fed in an upright position and kept upright at least 30mins after feeding. Thickening with rice cereal is also standard, especially with breastmilk since it is thinner than formula. It will not destroy their digestive systems or cause food allergies, although statistically reflux babies are more prone to food sensitivities. Eventually, the LES muscle (the muscle that controls the opening/closing of the flap between the esophageus and the stomach) will strengthen and function properly and the baby will stop spitting up. This is different for each child. Mine were 9mos, 6mos. And 4mos. Most likely the ped will put the baby on Zantac or something similar to prevent the production of acid so that they don't scar the throat while refluxing, which can introduce more food issues.
It can be a scary thing to go through, and frustrating at times. Just know that it doesn't last forever. If she has concerns, she should consult with a Ped GI. All that said, my daughters are now healthy, happy 6, 7 and 10 year olds with no food issues whatsoever! Hang in there, there is a light at the end of the tunnel!