It was a copy/paste error to include the reference to Conway; from what I have read about him I very much doubt he expects instant, the next second, replies. Just reasonably prompt replies.
Which is not really what that point was saying.
I just think that the time between sending and email and a reply is not a good measure of how important you are to that person. Certainly, if someone replied within a few seconds of my email to them I'd have to pause and question why they responded so fast. Are they literally desperate for my input? Why? (of course, usually being desperate for that input is fine, and part of being excited to have a chance with someone who can really help you - but occasionally it is a marker of someone dodgy).
Basically: it seems something of a shallow way to judge things.
Also, there's a pecking order. If you are some unknown founder who really needs Conway you should respond as fast as humanly possible. On the other hand, if Conway wants something from Steve Jobs he probably should respond quickly.