Agree that this isn't that relevant for cs interns. But smaller startups don't hire interns in 6 months in advance. There are still great people available and it would be odd for them to prioritize hiring an intern that far in advance.
Don't think buzz is a good reason to be "stealth" either - very few companies get buzz because they were stealth. there is also a difference between being stealth and just not yelling from the rooftops about what you're doing. The latter is usually enough to make sure you don't get covered before you want to.
Isn't this the great catch22 for a lot of successful people? What drives them to be successful is never being satisfied, but it's also what might mean they'll never be happy?