It can form part of an appeal but, as admissions says, it depends how much the school still does now that the funding is gone. For example you would be in a stronger position if you could show this school is the only one in the area that offers Maths, Further Maths and Statistics with the others just having the basic options. You could then say that this school would be beneficial to a child who is strong in numeracy. The same would apply if the school ran special clubs or maths groups that the other schools did not or otherwise had 'maths' opportunities.
Some schools however make barely anything of their specialist status so, if there were no actual differences in what each school could offer a student who was strong in numeracy, the label itself would make little difference at appeal.
There are some schools who do select partially on the basis of aptitude for a discipline and that is in the admission criteria but the vast majority of schools do not and their specialisation has no bearing on admissions You need to understand the background to being a specialist school. In essence something like 80% of secondary schools had a specialism of one sort or another and by having gained that "award" they got a nice big pot of funding. That specific funding now no longer exists and therefore there is actually no need for schools to have specialisations. Having said that many schools really did have and still have significant expertise in the area that they chose, so it could benefit your child if you got a place in the school.
Our two closest schools are 1 technology and ICT specialist school 2 performing arts specialist school
The 3rd closest is maths and computing.
DS1 (who is only in y3) has been on the G&T register for numeracy since yr 1. Is there ANY ammunition here for an appeal if he fails to get into school 3? (ie that it's our closest maths specialist college) There is nothing in the admissions criteria for school 3 to favour him.
Sorry if it's a daft question. I just don't understand the point of having these specialities if talented children can't benefit from them.