> “Jizz” was chosen because it sounds like “jazz”, but different. We can infer that the person who chose the word meant to convey that jizz music is like jazz music but different.

“Jizz” in English is etymologically closely related to “jazz” in English, which some sources also attest to having a (historical) slang use identical to that of “jizz”, so, while you are absolutely correct about the point of choosing the word, that point is quite compatible with the person doing so of being aware of the slang use of “jizz”.