I don't know any of the people involved in this patch, so I've sent it to Alexander Korotkov to get his opinion. I'll let you know his response after he has a chance to look at it.
> This is very long story starting from 2017. This patch should finally be committed. Some preliminary infrastructure already landed to PostgreSQL 16. Regarding SQL/JSON itself I doubt it will be committed to PostgreSQL 16, because feature freeze is coming soon. It's likely be postponed to PostgreSQL 17.
> Regarding replacement for pg_jsonschema, I don't think it will be a good replacement. Yes, one can construct a jsonpath expression which checks if particular items have particular data types. But I doubt that is nearly as convenient as jsonschema.
It looks like there would still be some benefit for pg_jsonschema, unless the community decided that they wanted support jsonschema validation. We could propose this, but I don't think it would arrive to pg core any time soon.
