KAFKA-3073 adds topic regex support for sink connectors. The addition requires that you only specify one of topics or topics.regex settings. This is being validated in one place, but not during submission of connectors. We should improve this since this means it's possible to get a bad connector config into the config topic.
For more detailed discussion, see https://github.com/apache/kafka/pull/4151#pullrequestreview-77300221