So, this is bullshit. You can keep secrets as long as the people involved think secrecy is warranted.
Google have an astonishing track record of not leaking projects to the press. They've worked on some incredible stuff, and the vast majority don't get leaked at all, or get leaked accidentally. Huge numbers of internal/infrastructure projects never get told about outside the company. Sure, some projects are pre-announced because by working with outside companies they assume there will be leaks (ChromeOS, Android).
Internally people get told "Please don't leak unannounced projects. A leak could cause your co-workers to have to launch an unfinished or unpolished project ahead of time, reducing the impact of months or years of their time".
The problem with Apple is that they work with a lot of outside agents, all of whom can leak without thinking of the personal consequences to friends, just financial/legal ones (which can be avoided). Their own engineers have a pretty good track record of keeping quiet about 'important' things.