I think the PG community is pretty aware that there are some issues with search engines taking users to the right versions of the docs. You google something simple like "postgres drop column" and the first postgresql.org result takes you to the v7.4 docs - EOL over a decade ago. It's a similar story for many searches, lots of results take you to v8 or v9 docs first.
(Note that if you've clicked "current" in the docs before, it will automatically redirect you. This is more relevant to newer users, and the actual links on google).
I do not have the personal expertise to help this situation at all, but I would like to call attention to this active thread for the rust docs repo - https://github.com/rust-lang/docs.rs/issues/1438. The corresponding site docs.rs has similar issues of always linking to outdated versions, and they're currently in the process of working to improve things. The thread contains a good bit of findings and trial/error. Knowing that PG has similar issues, it seems like there is a possibility of benefiting from mutual lessons learned in improving SEO and linking.
Again, I have no concrete proposals to make, but wanted to draw attention to the issue and a good thread of ways to improve / possible solutions.
