Has the school evaluated him?
It depends on how reasonable your school/school district is. Our last IEP meeting was a disaster/circus show with people arguing about every single thing that we said, including comments such as "Too many kids are on IEPs", "What good would services do anyway, she's just going to be pulled out with 6 other kids" "Your DD has a lot of strengths and she doesn't need to be good at EVERYTHING.", "There are other kids like her and it's not a big deal", etc. etc. etc. Meanwhile the eval report had completely abnormal results for things like executive functioning, poor classroom observations in terms of her being on-task, and a 40-point gap between cogniitve ability and writing achievement. The special education director was sitting right there at the table and said nothing.
Needless to say I filed formal complaints with the State, an investigation was opened, and I put in a request for an independent eval at public expense. The school is now willing to cooperate with us, now that they are seeing more dollar signs (maybe! I'll believe it when I see it).
Most schools/districts are not that bad and if they have been cooperating with you so far the meeting will probably be fine/normal.