By taking this step, the PostgreSQL community set up an invaluable real-world litmus test that lasted an entire year. This strategic intolerance allowed them to gather critical insights into whether any existing code would break and to understand whether such cases were intentional or not.
The decision significantly de-risked the introduction of the new, much-welcomed syntax in SQL and PostgreSQL 16. I think this decision framework serves as a model for other projects on how to introduce changes responsibly without breaking the ecosystem.
Kudos to the PostgreSQL team for such thoughtful engineering and to Peter Eisentraut for leading this exemplary four-year journey!
[1] The Harmful Consequences of the Robustness Principle: https://www.ietf.org/archive/id/draft-iab-protocol-maintenan...