If his reading comprehension level now isn't significantly different relative to his peers than it was in 2011, I'm curious:
Has he been given remediation for his dyslexia? (I'm guessing he has?) If he's been in a program where he's been receiving remediation, you'd expect his functioning relative to his peers to be at a higher level now. (I think - but I'm just a parent, not a professional, so take my questions and advice with a huge bottle of salt
).
From my totally non-professional point of view, I'd think that the fact that his reading comprehension is measuring at low average is the important point to make here, and that it points to lack of adequate remediation - unless his other cognitive abilities measure at low average too.
Sorry I'm not much help - I hope things go well for you at the hearing!
Best wishes,
polarbear