Regardless of technical merit, I don't think it stands any chance of adoption without major users. Specifications and standards are only really valuable as a contract between two or more parties, otherwise they might as well not exist.
On the tech side:
- RegExps open yourself up to RegExp-based DoS attacks.
- The nested/denormalized results anti-pattern seems to be copied from GraphQL. Unless this is intended to be a faithful reproduction, don't copy mistakes.