The uniqueness constraint on label-descriptions can now be violated. This is due to the function itself is modified in TermSqlCache::termsToConditions() (https://gerrit.wikimedia.org/r/#/c/25006/7/repo/includes/store/sql/TermSqlCache.php)
The function could be duplicated into a new with both the functionality of the old and new version of the code, or a new subclass can be made. In the first version a new TermSqlCache::getMatchingTerms() could be made to support it. In the second one the StoreFactory::newTermCache() must be changed.