Hi all!
This is a quick heads up that we just switched testwiki (test.wikipedia.org) to $wgMultiContentRevisionSchemaMigrationStage = SCHEMA_COMPAT_NEW [1]. We will do the same for all WMF wikis soon[2], and make this the default for new installes of MW 1.34[3].
In concrete terms, this means that the following fields will no longer be populated: rev_text_id, rev_content_model, rev_content_formt, as well as ar_text_id, ar_content_model, ar_content_formt. All code should now use the slots table to join against the content table to find the relevant information. This should already be the case for all code in core as well as all extensions maintained, deployed or bundled by wmf. The unused fields will be removed eventually.
If you notice any oddities on testwiki that might be related to this change, please file a ticket on Phabricator and tag #Core_Platform_Team.
Cheers, Daniel
[1] https://phabricator.wikimedia.org/T198558 [2] https://phabricator.wikimedia.org/T198312 [3] https://phabricator.wikimedia.org/T231673