Bastien Nocera created an issue #574:
It should probably redirect here instead: https://wiki.gnome.org/Community/GettingInTouch/IRC although that page is probably not really up to scratch.
(I should also add that, anecdotally, GIMP/GIMPNet was considered an ablist slur for a potential contributor, and around the same time, we finally had an irc.gnome.org address, and started moving services into the GNOME org. I'm sure there are folks that know that timeline better than me, but it shows that the irc.gnome.org name is wanted, and shouldn't redirect to a gimp webpage)