NiFi provides a number of Kafka processors based off the Kafka Client they are using. The original ConsumeKafka processor (no number) used the old Kafka 0.8 client. The 0.8 client processor does not offer the ability to specify a regex for the topic names. You should be using the Kafka client version processors that match the Kafka server version you are consuming from.
From ConsumeKafka_0_10  on, you have the ability to configure the processor to use "names" or "pattern" for the topic name(s).