No one receives it.
“Nondurable subscribers receive messages only when they are actively listening on that topic. Otherwise, the message is gone. In the pub/sub model, there is no real concept of a “topic” holding all of the messages; rather, when a message is received by the JMS provider, the provider makes a copy of that message for each subscriber. If the subscriber is not active, it does not receive a copy of that message.”
If you allow the dynamic creation of durable subscribers, keep in mind the storage for those messages may greatly increase.