Not questioning whether or not that is true, have no idea, but that is truly one of the more ridiculous things I have heard if it is true. So an 18 year old who has never written a check is expected to understand changes to a form that most adults have trouble with?! Amazing.
Also, in this case, how would the student even know that the income may have been assigned to the wrong parent unless the parent told him after viewing the form? In many families the children do not know the specifics of their parents income and assets.
OP, when you say “we were notified” is that both of you or just your child? If OP was notified of the change it does not make sense that she was notified and then is not allowed to view the change without asking her child to give her access?