Status Report breaks with 'Requested a non-existent service "search_api.theme_switcher"...'

After upgrading to search_api 1.30 and search_api_solr 4.3, search_api_solr had four new hook updates that were not applied:

• 8418 - Replace WhitespaceTokenizer with StandardTokenizer.
• 8419 - Adds missing solr.FlattenGraphFilterFactory to index analyzers.
• 8420 - Add Solr 9 configs, don't build suggesters on commit, add offsets for unified highlighter.
• 8421 - Install new Korean configs.

Once drush updatedb along with the drush cache-rebuild were both executed via the CLI, the WSOD disappeared from /admin/reports/status. The error message for WSOD unfortunately does not easily lead to a solution.

After upgrading a module, running update.php/drush updb and clearing the cache is standard practice. If that’s all it takes to resolve this problem, I wouldn’t consider it a bug.