As of 1.27.0-wmf.22 (deployed to WMF wikis April 26-28) and MediaWiki release 1.27 (specifically, this change https://phabricator.wikimedia.org/rECHOb10bd700333d2eef10c7df0a9946b87fd451f81b in Echo), meta=notifications will return its result as an array rather than an object.
Previously, the meta=notifications output looked like:
{ "query": { "notifications": { "list": { "12345": { "id": "12345", "type": "edit-user-talk", ... }, ... }
Now, it looks like:
{ "query": { "notifications": { "list": [ { "id": "12345", "type": "edit-user-talk", ... }, ... ]
My apologies for the late announcement, and thanks to APerson and Cienca Al Poder for noticing https://phabricator.wikimedia.org/T138690 and encouraging me to write this announcement.
mediawiki-api-announce@lists.wikimedia.org