i just set $wgWBClientSettings['useLegacyUsageIndex'] = true; locally.
now when running jobs in my client (after removing a site link), i get:
Catchable fatal error: Argument 1 passed to Wikibase\Client\Usage\UsageAspectTransformer::transformPageEntityUsages() must be an instance of Wikibase\Client\Usage\PageEntityUsages, integer given, called in /Library/WebServer/Documents/php-master/extensions/WikidataBuild/extensions/Wikibase/client/includes/Changes/AffectedPagesFinder.php on line 349 and defined in /Library/WebServer/Documents/php-master/extensions/WikidataBuild/extensions/Wikibase/client/includes/Usage/UsageAspectTransformer.php on line 84
Call Stack:
0.0006 664488 1. {main}() /Library/WebServer/Documents/php-master/maintenance/runJobs.php:0
0.0033 1207792 2. require_once('/Library/WebServer/Documents/php-master/maintenance/doMaintenance.php') /Library/WebServer/Documents/php-master/maintenance/runJobs.php:95
0.0975 19139104 3. RunJobs->execute() /Library/WebServer/Documents/php-master/maintenance/doMaintenance.php:102
0.1157 19273816 4. JobRunner->run() /Library/WebServer/Documents/php-master/maintenance/runJobs.php:80
3.3446 28498392 5. Wikibase\ChangeNotificationJob->run() /Library/WebServer/Documents/php-master/includes/jobqueue/JobRunner.php:135
3.9161 37087648 6. Wikibase\Client\Changes\ChangeHandler->handleChanges() /Library/WebServer/Documents/php-master/extensions/WikidataBuild/extensions/Wikibase/lib/includes/ChangeNotificationJob.php:133
3.9179 37238648 7. Wikibase\Client\Changes\ChangeHandler->handleChange() /Library/WebServer/Documents/php-master/extensions/WikidataBuild/extensions/Wikibase/client/includes/Changes/ChangeHandler.php:142
3.9182 37239240 8. Wikibase\Client\Changes\AffectedPagesFinder->getAffectedUsagesByPage() /Library/WebServer/Documents/php-master/extensions/WikidataBuild/extensions/Wikibase/client/includes/Changes/ChangeHandler.php:167
3.9182 37239240 9. Wikibase\Client\Changes\AffectedPagesFinder->getAffectedPages() /Library/WebServer/Documents/php-master/extensions/WikidataBuild/extensions/Wikibase/client/includes/Changes/AffectedPagesFinder.php:114
3.9362 37853264 10. Wikibase\Client\Changes\AffectedPagesFinder->transformAllPageEntityUsages() /Library/WebServer/Documents/php-master/extensions/WikidataBuild/extensions/Wikibase/client/includes/Changes/AffectedPagesFinder.php:182
3.9368 37893304 11. Wikibase\Client\Usage\UsageAspectTransformer->transformPageEntityUsages() /Library/WebServer/Documents/php-master/extensions/WikidataBuild/extensions/Wikibase/client/includes/Changes/AffectedPagesFinder.php:349checked in production and don't see anything in the logs about this, but it could be it's just not being logged at the moment.
when i removed a site link for (fr)wikivoyage, I do not see the change being reflected in the other wikivoyages or in frwikivoyage, nor see it appear in my watchlist.
i tried removing a wikipedia site link from the same item, and the change did get reflected on wikipedia and in my watchlist there. (wikipedia is running older Wikibase code).