PostgreSQL 13: native JavaScript Procedural Language support ?

Hi and hope this finds you well,

PostgreSQL has state of the art JSON(B) data type and query support, and basic updates as well, eg jsonb_set().

How about enabling users to do more advanced processing of JSON data inside the database itself, using JavaScript?

There's the PLV8 extension https://github.com/plv8/plv8

but it's not available for many major db providers (eg Heroku), making it hard to adopt it. Having it supported in the standard PostgreSQL distribution, besides the existing 4 languages (https://www.postgresql.org/docs/12/xplang.html), would be awesome!