I used to work in Special Ed for the San Dieguito HS District and I thought the program was very good. However, I think a lot of that had to do with the teachers who were there at the time.
Teaching Special Ed can be very draining and there is a lot of turnover (I teach regular ed now) so I don’t know if the programs are still as strong as they used to be.
The parents who were armed with knowledge, especially the ones who hired an advocate, were definitely accommodated and their kids were taken care of. The best thing you can do as a parent is be a vocal proponent for your child if you want the school to provide services for him.
I know your son is still quite a few years away from high school but that was my experience.