Sometimes your employees can tell things aren't going well, and you bald face lying to them like this will make them leave even faster.
This is also a great strategy to fuck people over, where if they believe in the stability of the company right until the day layoffs are announced they might have just bought a house or something else that will make the next few months for them excruciating, if not disastrous.
So please don't take this advice to the extreme imo. I'm not saying you shouldn't be positive, or give every detail. But you should be realistic. Save the rose tint for the investors and just make sure people have what they need to do their best work, within your power.