In my experience they'll only formally recognize what's shown up on test results from established pros, so I'd bring in whatever you have (if you haven't already).
You either ask for a modification of this section:
"behavior specialist be included in (DS)'s team to assist in determining if suggested strategies and specifically designed instruction are sufficient at the time his IEP is developed or if a functional behavior assessment should be initiated."
...to include mention of 2e, or have somewhere prior something that mentions that your DS has been identified being 2e and is therefor subject to frustrations and anxiety from the limitations that his vision challenges place on his intellect.
(or something like that)
I'd be really "team-oriented" though, because you want to keep the lines of communication open. It sounds like they're trying to accommodate him, which is good. You can express your fears that a functional behavior assessment could result in a misdiagnosis because of the 2e, and see what they say.
Good luck
