Re: run-hooks vs. run-mode-hooks.

[Richard Stallman]

    Is it possible to use run-hooks in those Emacs versions?

Yes, but it won't always be correct.

    Maybe Gnus can do something like:

    (or (fboundp 'run-mode-hooks)
        (defalias 'run-mode-hooks 'run-hooks))

Definitely not!  Gnus should not mess with the way Emacs defines
(or doesn't define) these functions!

Gnus should define a function called gnus-run-mode-hooks, which calls
run-mode-hooks if that is defined, otherwise run-hooks.  Then all the
modes in Gnus could use gnus-run-mode-hooks.