src/TaggableBehavior.php
public function afterDelete()
    {
        // after complete owner delete delete tags links
        if (!empty($this->_tagsForDelete)) {
            $relation = $this->owner->getRelation('tagsList', false);
            if ($relation instanceof ActiveQuery) {
                /** @var ActiveRecord $class */
                $class = $relation->modelClass;
                // decrease counters
                $class::updateAllCounters(['count' => -1], ['in', $class::primaryKey(), $this->_tagsForDelete]);
                // delete links
                $this->owner->getDb()
                    ->createCommand()
                    ->delete($relation->via->from[0], [key($relation->via->link) => $this->owner->getPrimaryKey()])
                    ->execute();
            }
            $this->_tagsForDelete = [];
        }
    }
public function afterDelete()
    {
        // after complete owner delete delete tags links
        if (!empty($this->_tagsForDelete)) {
            $relation = $this->owner->getRelation('tagsList', false);
            if ($relation instanceof ActiveQuery) {
                /** @var ActiveRecord $class */
                $class = $relation->modelClass;
                // decrease counters
                $class::updateAllCounters(['count' => -1], ['in', $class::primaryKey(), $this->_tagsForDelete]);
                // delete links
                $this->owner->getDb()
                    ->createCommand()
                    ->delete($relation->via->from[0], [key($relation->via->link) => $this->owner->getPrimaryKey()])
                    ->execute();
            }
            $this->_tagsForDelete = [];
        }
    }
After delete event