No you can't, JSON is not JavaScript and eval is not capable of working on all correct JSON documents. JSON requires a JSON specific parser. So this breaks nothing, eval doesn't work now and JSON has never been JavaScript.
> JSON is literally a JS object literal (with the additional requirement that any key be a string).
Which makes it not a JS object literal but a near subset with slightly different rules with unicode strings that make it not even a subset.
So now you're wrong twice.