Whatever the reason for "hiding" Mythos, it seems clear that these systems are getting very good at finding software security exploits. Mythos has made more people, even the US government, sit up and pay more attention. Regarding who should control the release of powerful systems like this, as Bruce Schneier and David Lie write in "Mythos and Cybersecurity" :

"Until that changes, each Mythos-class release will put the world at the edge of another precipice, without any visibility into whether there is a landing out of view just below, or whether this time the drop will be fatal. That is not a choice a for-profit corporation should be allowed to make in a democratic society. Nor should such a company be able to restrict the ability of society to make choices about its own security."

https://www.schneier.com/blog/archives/2026/04/mythos-and-cy...

It is reasonable to be concerned.