I fail to see how this is relevant. Your code feeds JSON to SQL, that remains supported. Or your code fetches SQL-generated value from SQL, in which case as literally stated before the JSON5 listing:
> JSON text generated by [JSON] routines will always be strictly conforming to the canonical definition of JSON.
Of course not, but I do have code that generates SQL and which uses JSON. (And no, the code in question is not subject to SQL injection.)