I think a lot of LAs have the strategy towards ABA - keep it small, keep it quiet, or everyone will want one. So they avoid going to public tribunal, but just give the ones who shout loudest the funding (or at least they fund ABA till about age 7, when they start jumping around and saying "all kids should be in school by 7" - an unlawful blanket policy line which was used on me.)
It is very interesting that it has stayed so small, it is hard to get ABA more in the public eye.
And because most newly-diagnosed mums' channels of information are controlled by LAs, the word about ABA never gets out, except on an open forum like Mumsnet.