Given that those files haven't been updated since 2018... I doubt that multiple versions would ever be a consideration. However, you can use the build_html.sh or build_html.bat scripts to build the HTML format locally.
...and the documentation link page hasn't been updated since 2019. Now can't somebody go in with vi or something and fix the PDF links issue, then make the appropriate directory on the web server listable?
I couldn't find your bugreport, so I raised it on core. Michael said a http mirror of FTP exists at
http://downloads.freepascal.org (note that is HTTP, not -S)
So something was done, just the links not updated.
This seems to be another of those cases- of which I've seen several in the past of "this isn't strictly part of the mainstream project, it's not my responsibility".
Well, thanks for responsibly opening a ticket then. Which number is it btw, so that I can close it ?