A well meant, but misguided proposal. As the author of the article indicates, this can become very, very costly, without any guarantees that it will significantly improve care for the disabled.
The person who has to choose between the option of private school and public is not the person who has to pay the bill. This way, the price will be completely left out of the decision. As long as private schools can offer slightly better care, they will be chosen by the parents. The schools will know this and start to offer this slightly better care, but they will also know they can ask any price they want and it will be paid.
The end result : Disabled childeren go to expensive private schools and the state pays the vastly inflated bill. It's not that I have a problem with the state supporting the disabled, but if the money that would be given to private schools is given to public schools, it could improve the care for the disabled a lot more then this scheme will.