Sadly, we do seem to have lost the ability to find old versions. Searching for example for "pg_stat_statements 9.6" for me still gives the 14 version, and the 9.6 version only in Russian off the pgpro site.
I remember this concern, and it's a shame there isn't a good solution to both.
Another concern that was raised previously was whether we'd lose the reputation that had been built up, but I'm still seeing the docs in the top search position almost all of the time. It would be good to check whether overall traffic, or average position, are down at all though.
So it appears that there is a traffic shift to the most recent docs based on the rel=canonical change.
