I'm the co-chair for the industry working group that maintains the spec that is the basis for ISO 19464 (AMQP). There's no money flow coming this way that I am aware of, and the contributing parties are fine with the spec being public, as demonstrated by OASIS offering downloads.
For this reason, considering the value of standards, their economic and social importance, the costs of their development and maintenance, we and all ISO Members have the interest to protect the value of ISO Publications and National Adoptions, not making them publicly available.