The comments give several examples of its use prior to the publication of Catch-22. It's difficult to know the extent to which Heller was aware of these, but at a minimum, he technically wasn't the inventor of the term.
@PeterShor mentioned the OED citation "1949 Amer. Speech ... The magician may speak of disappearing or vanishing a card." @user14111 also mentioned "1897 Chem. News 19 Mar. 143 We progressively disappear the faces of the dodecahedron."
It's quite possible that Heller thought that he invented the term. On the one hand, he had degrees in English and taught English in college, so presumably would've been aware of the existence of the OED; that being said, it's possible that he had read the entry.
The fact that Yossarian was baffled by the use and insisted that the word made no sense in its context would suggest that the characters didn't know about the usage, and possibly that the author didn't, either. While that technically doesn't prove the point, I think that the most likely explanation is that Heller simply didn't know about other usages and thought that he was inventing the phrase (which he technically didn't). It wouldn't be the first time he invented (or tried to invent) terms, either.
TL;DR Heller didn't technically invent the usage, but it's quite possible (even perhaps likely) that he thought that he did. Either way, the book was instrumental in popularizing the usage.