Hi
Firstly ,even if you know something like that it hurts (have experience of it), so if you don't agree that must be ahrd for you.
I would write aletter to the SENCO asking them to formally outline their reasons for the emergency statement review (as it is termed).
It may be that their concersn are not at all academic and related to the sort of thing that can't be easily spotted in a report- we're trying to get ds1 a place in a AS class for Comp as although his grades with a lot of support are average - above average, without that he collapses entirely, and his organisational, social and generalself care skills will place him at risk, could it be something like that?
You need to get every scrap of information togather that you can, then really go through it bullet point by bullet point to outline your take. You ahve to be honest with yourself, and it would be good to get someone else read through (I am the Queen of Denial,me) but as a parent you know your child the very best.
I would start with an action plan of:
ask for written explanantion then arrange pre-review meeting to make sure you have all the facts. Whilst awaiting this, contact IPSEA, SOS!SEN and whatever the organisation for your son's DX is (if he doesn't have one, cerebra or someone more generic).
Ask him how he feels as well, ds1 refused a schoolmove until I cottoned on that he hadnt picked up everyone moved at that age anyhow- at which point the idea of more supportive schooling became attractive to him.
Don't agree to anything until you know what's available in your area.
And be aware if it is aprivate or academic school that soemtimes a few sods will try and get rid of low achieving children to up a grade average. rare I am certain, but something I have heard of anecdotally (and would assume our school did- ds1's SATs were bumped up from 1 to 2 becuase 'Oh we think he could be mroe capable really'- at that satge he couldn't).
HTH, good luck