I agree that having the ability to construct objects/arrays that are compared by nested values, rather than references, will be useful.
But, given that Immer already exists, and only meaningfully requires ES6 Proxy support, I'm not sure how much of an impact the availability of Records will have.
In the case of RTK specifically... Immer is built into `createSlice/createReducer`, and it's _always_ getting called even if you manually create an immutably-updated result yourself. So I don't see any real change or benefit there.
https://tc39.es/proposal-record-tuple/tutorial/