Man, that is a classic "Jobs" reply. Detailed, well-reasoned email, acknowledged by a curt one-sentence reply. But that only happened in email. I don't think Jobs liked the written medium. He could talk up a storm. One of the best declarative public speakers I've ever heard (but not an "emotionally eloquent" one, like many preachers).
Don’t think that’s as much a “Jobs” reply as just a general senior management necessity. With the amount of “important” emails you get in a position with any kind of responsibility, writing thoughtful elaborate responses to each and every one would leave you with no time to do your actual job. So you communicate the core message clearly and bluntly, and move on to the next fire.
Also, I don't see what other information was needed here. He was the CEO, he was not supposed to get into implementation details. He gave a green light and left them to do their job.