What Kafka actually published himself, in short-lived journals and limited editions of very slim volumes, amount when collected to some 300 pages. Brod Brod took the publication of these as sufficient justification for publishing the rest, the bulk of Kafka’s writing, thereby (it is said) ignoring the advice of a Viennese wag, whom he anxiously consulted about the propriety of such a step, and who said he was sure it would be all right, if only Brod destroyed some unwanted writings—why not his own?
( Source: Anthony Thorbly – Kafka's Narrative: A Matter of Form, in Bloom, H. (ed.): Kafka, p. 23. )
Could you explain to me the meaning of the word "wag" in the context of the sentence. The possible meanings of this verb does not fit. Is the meaning of the second part of the sentence as follows: Brod ignored and did not destroy Kafka's literary work. In fact he ignored the advice of a "Vienesse wag" (?) who recommended to destroy only minority ("unwanted") of Kafka's work. What is meant by the appendix "why not his work?". Is this related to Brod's literary work?