Steve Jobs comes by and every employee tells him that he can't ask what they're working on and they all quit the next day? That sounds a little hyperbolic.
Admittedly I only saw Steve doing this like two or three times. The group that was next to mine was not large and was gone in about a week. Heard similar stories from others who observed Steve Jobs randomly talking to people who then left and also heard some of these people talking about these events. Morale was very low in many groups at that time and a lot of people working there had quite remarkable egos.
Doesn't it seem more likely that the CEO (or proto-CEO, you didn't clarify what time period this was) fired these people after they were uncooperative in these informal talks?
On at least one occasion an employee posted on an internal discussion board that they were offended and quit out of what they considered basic defense of dignity and protocol. In terms of the whole group being gone in a week? Sure, at least one of those people were probably fired. I was really busy at this time so this is a highly subjective recollection based on my point of view and my interactions with others in person and on the highly active employee message boards.
The Apple employees who I observed encountering Steve Jobs this way all left the next day and at some spoke about this with others and one posted on an internal message board about their experience. Did Steve Jobs attend all the tens of thousands of Apple employees in this way? Probably not. That this happened once seems remarkable. I'm sorry my attempt to recall colorful moments triggered this reactive detective thing in you. To me it seems that trying to present this is worth this risk of misunderstanding. It was a strange time.