In most companies above 1000 employees it's assumed that any email/communication with most of the employees is as if you sent that communication to the NY Times at the same time.

You are looking for a conspiracy where there is none. For all practical purposes telling something to most of your employees is telling it to the world.

Which is why in most public companies, first you send the press release (to the news outlets, investors), and only AFTER you tell the employees.

Sam Altman deciding to tell it to the employees is the same as him deciding to tell it to the whole world, and he was well aware.

It was already rumored that Google is delaying releasing Gemini 3.5 Pro, supposedly because its not as good as they wanted. But maybe its because of Mythos level security capabilities.