As an editor who has:

• a page watchlisted (e.g. on metawiki)
• the Preferences setting enabled for Email me when a page or a file on my watchlist is changed
• the Preferences setting disabled for Show Wikidata edits in your watchlist

If the (metawiki) page's associated Wikidata item is changed, then

Current results:

• I receive an email saying that the (metawiki) page was changed, without any clue about what actually changed.

Expected results:

• If the preference is disabled for Show Wikidata edits in your watchlist - then don't send an email at all
• If the preference is enabled - then send an email with a clear description/link for what changed and where.

For example: I just got the following email.

Dear Elitre (WMF),

The Meta page VisualEditor has been changed on 8 March 2016 by
anonymous user 99.244.30.79, see
https://meta.wikimedia.org/wiki/VisualEditor for the current revision.

See
https://meta.wikimedia.org/w/index.php?title=VisualEditor&diff=next&oldid=15293484
to view this change.

See
https://meta.wikimedia.org/w/index.php?title=VisualEditor&diff=0&oldid=15293484
for all changes since your last visit.

Editor's summary: Language link added: [[:cy:Wicipedia:Y Golygydd
Gweladwy]] This is a minor edit

Contact the editor:
mail: No email address
wiki: https://meta.wikimedia.org/wiki/User:99.244.30.79

There will be no other notifications in case of further activity unless
you visit this page while logged in. You could also reset the
notification flags for all your watched pages on your watchlist.

Your friendly Meta notification system

I couldn't find any traces of that edit though, so I checked on Wikidata, and found it there instead.
The message is confusing.