I believe what they are trying to say is that at many high schools, there is no parental input into scheduling. That’s decided by the current year’s teachers/GC/student. There are exceptions - typically at the AP level and beyond - where the parent needs to sign off agreeing, as examples, that the class won’t be dropped and/or the AP exam must be taken.
However, if in your situation, the HS requires parental approval on course selection, then everyone else’s anecdotes are moot. Their school/their rules.
@skieurope… at my school, in order to take an honors class, you have to have a parent, the student who’s trying to take the class (me), and a teacher to sign the form. In order for you to take honors, you have to a certain grade (amount depends on teacher) in his/her class to take honors. Then that teacher signs off and you turn in the form to your GC.