504 Accommodation Request -Do I have to prove need?

[Smiley74]

I am trying to get an accommodation put back into my child's 504 regarding use of a planner.  It was removed by school. I have asked that it be put back as it was previously-

"Utilization of a planner to inform X and her parents of work she has and what needs to be brought home and brought to school."  Principal won't and is asking for me to justify her needs.  Do I need to provide justification of academic issues? If so what? It's already a recommendation in the psychologist report.

[JSD24]

What do the other students use?  My district had all teachers put assignments on Schoology so I think they did away with the need for planners.  (Schools are allowed to remove 504 accommodations w/o telling parents.  Parents are not required members of the 504 team.)

[Smiley74]

All students are given the paper agenda beginning in third grade, but not all the teachers use it in third. Use in fourth is a bit more widespread. We have Schoology but it’s not in use for elementary students. 
I know school can take out accommodations without parent consultation, but the principal is playing games with all accommodations taking them at face value. For ex the accommodation was rewritten to “access to a planner “ so basically she could be doodling in it all day and the principal is ok with that as its use. Dx for add exists already.