At en.wp Sherry has already removed the note to flag she is no longer watching there. We'll need to establish a new process with volunteers there, regardless of whether we'll centralise the feedback elsewhere or they'll keep it active.

FWIW at Wikimania I have finalised an agreement with @Cirdan (after his talk https://wikimania2017.wikimedia.org/wiki/Submissions/From_open_hostility_to_collaboration:_The_WMF,_the_VisualEditor_and_the_German-language_Wikipedia) that the German board is ready for volunteers takeover. He knows he can ping us there in case of need, and I'm going to add this note to that page as well.

Thank you @Cirdan!

Draft of the messages at https://www.mediawiki.org/wiki/User:Elitre_(WMF)/Feedback_centralization?venotify=created .

I have sent some 35 messages to all the wikis involved. In 2 weeks we'll see which ones are staffed by volunteers, and which ones aren't.

One-week update:

• IKhitron has kindly TL;DR my message at he.wp;
• Stryn (in charge of page at fi.wp) says "I'm also fine having the feedback page on MediaWiki";
• Cirdan will take care of the page notice at de.wp;
• -revi says "I'm fine it being migrated." at ko.wp, and that they can help further at mw.org if necessary;
• at it.wp Pierpao.lo agrees centralisation is the way;
• Lsanabria TL;DR my message at es.wp;
• I clarified our intentions for Kerry at en.wp;
• got support and an offer for help at ar.wp.

Looks like it's going well. Yay!

Ok, today is the day. Going to proceed.

Ok.
The feedback pages were/are in the process of being redirected, and the internal feedback tool can be redirected to mw.org as well, for the following 15 Wikipedias:

ilo, he, mr, sv, fi, bn, nl, ko, it, ja, hu, fr, fa, es, ar.

Instead, only specific notices about WMF staff not monitoring will be put up at de. and en.
The German Wikipedia in particular seems to address off-topic feedback locally anyway, so I'd say, no need to change anything for this wiki.
I do not have an opinion about what to do with feedback from the tool at en.wp, but I don't think it's the end of the world if we redirect that bit of feedback to mw.org.

Wikidata doesn't seem interested in deleting the page that collects all the link to the (mostly now dead) local feedback pages, FWIW.