There are reasons to publish a press release. Maybe you think Bitcoin (and other POW mining) is destroying the environment and you want to shut down the entire ecosystem instead of profiting from it. Maybe you prefer to be famous for an intellectual achievement instead of rich. And if you publicly cracked SHA256, I'm sure you can get a job that pays pretty well working on other projects.

Now, if your goal is maximize wealth, then I don't see a reason to publish a press release.