This is an announcement for a significant (but not breaking) change to the JSON output of WikibaseLexeme entities, specifically of Senses and Forms, when obtained via Special:EntityData or the Wikibase API endpoints like Special:ApiHelp/wbgetentities.
The Snak output in the Wikibase JSON serialization usually contains a
datatype field for each Snak. Previously, these fields were missing for statements within Senses and Forms of a Lexeme – see the message on Project Chat for an example (I didn’t want to bloat this email too much by including it here 🙂). Starting on 26 August 2020 (barring unexpected deployment issues; 25 August 2020 on Test Wikidata), these
datatype fields will be present there as well.
If you have any issue or question, feel free to leave a comment at T249206.