It's exactly the same in the case of Rollout, they were also only updating JS using JavaScriptCore, not using new native APIs.
The clause of the app store guidelines is not just about code; it also forbids gaming the review process for adding features or changing the app purpose without an explicit review. This is regardless of the language used to write the app.
About react-native-invoke: https://medium.com/@talkol/invoke-any-native-api-directly-fr...
The GitHub page has been set to private for ... reasons I can't divulge, but the NPM package is still public.