Verbal means nothing until the NLI is signed in their senior year. Once that is signed, it is a contract and now both parties are binded by that contract. I don't think that it looks good for a school to go back on an offer but I think you will see schools doing that and also girls changing their committed schools because it is happening way to early and when you are in 8th or 9th grade how could you possibly know what you want in a school and your future. From the schools perspective, offering a kid a spot who hasn't even gone through puberty and what not. Bodies change a lot in that 4/5 yr period. What if a school gives a verbal to a freshman, freshman accepts and then barely competes the rest of her HS years for injury or whatever, hasn't improved like was expected, I cannot see a school honoring that verbal agreement.
For my dd, she was not offered her scholarship until her senior year. She had to have a pre-read done and once admissions told the coach that she could get into the school on her own merit, it was then that he offered her the scholarship. I do know that times are changing though as some juniors have already verballed to her school now so times are a changing!