Implementations already exist, such as react-native-invoke, that enable similar functionality. The jump from "need to explicitly bridge" and "explicitly bridge the runtime API" is very small, opening the possibility of exactly the same features as Rollout.
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.