The @pnpm/meta-updater package helps keep configuration files up-to-date in a monorepo by applying custom updater functions to meta files like package.json and tsconfig.json. It's designed for developers working with monorepos who need to maintain consistent configuration across multiple packages. The tool can be used to automatically update, add, or remove configuration settings and can be integrated into CI/CD pipelines to ensure all meta files are current before running tests.