More like. UK high court dose not have the authority to enforce gov treaties. Only laws as created by the UK parliament.
If the UK parliament allows laws that break treaties like the Geneva Convention. Only other signees of that convention can do anything to stop them.
This whole idea of international law is not really a thing. Just agreements between nations and political will to enforce them.
Not to mention. The concession is basically. Wait for a report. With 0 requirement to follow the results of that report.
So you can fuck over the support for disabled independence. But must wait a while. If the MPs considered this in anyway a requirement. They would wait for the report before passing the law.