Mike McLean writes:
> So if I do not copy/move/link code from contrib/lisp/ to lisp/ I could
> still be using old contrib code from my Emacs system directories?

There is no contrib code in Emacs unless you yourself installed it
there.  The advantage of copying to lisp is that you don't need to add
contrib to the load-path and mostly don't need any further setup beyond
(require 'org-install).