No, it's not.
The idea that you can waive the implied warranty of fitness for a particular purpose covers good faith mistakes or omissions. It doesn't cover intentional misrepresentations or excuse blatant fraud and criminality. For instance, if you sneak in a ransomware package, it's not "all good folks" because "there's no warranty, it's my repo and you can munch on my nuggets."
The author offered something to the community on certain terms and made certain representations. The author then decided that they had sellers remorse, and instead of acting like a professional adult who realized they made a poor investment (and finding a new maintainer), they threw a tantrum and decided to try and stick it to "the man" by violating the representations they previously made to the community as a whole.
This was petty, petulant and in bad faith. Does it rise to the level of criminality? It might, IANAL though. Nobody's going to go after them because it was more immature than truly harmful.