Modern SQL standards seem to be primarily written by the PostgreSQL team - new features they roll out and syntax to describe them tend to be widely adopted. Granted, it could be coming out of ISO itself but nobody would be able to tell since their standards aren't openly published.
ISO standards are often discussed at PostgreSQL conferences, and whenever possible they try to follow the standards. Sometimes standards are written after PostgreSQL implements a feature, and it some cases it seems like they are even written to accomodate PostgreSQL (eg. the SQL/JSON standard seems to take into consideration that a database might have multiple JSON types just like PostgreSQL)
But whenever the topic of standards comes up, someone immediately mentions the high price of the standards, and I think only some of the developers actually have a copy of the SQL standards.
