Because it sounds more like a general e-mail to MS staff who do not work on the new XBOX yet are getting bombarded with questions just because they work for MS.
Just because you work for a company in one division does not mean you have knowledge about every other aspect of that company's business or products.
why do people not working on the system need to know the info in the email? all they have to say is MS doesn't respond to rumors.(like everyone that has been defending their position has said) the email just doesn't make sense unless they were going for required online and then changed it after the backlash of the leak.