Does the Child Status Protection Act apply to my brother?

The Child Status Protection Act only applies to the children of U.S. Citizens. Based on the information you have provide it doesn't seem that this would be of any help to your brother. However, once your parents obtain lawful permanent residency they can file an I-130 for your brother and he would be in the 2A or 2B preference category and the petition will be processed much faster than the current I-130 which is 4th preference. The Child Status Protection Act might help keep him in the 2A category but it depends. Hope this helps.