Not too sure about how I feel about a Direct potentially being next week.
On one hand, it makes sense. 2 weeks ago, we got a Nindies, one week ago we got a Pokemon Presents, and they seem to be taking a break this week due to Gamescon, a Direct next week would effectively 'keep the ball rolling' as it were.
Though, I could also see them waiting until the 2nd week of September as opposed to the first.
There's no solid 1 week in September that September Directs tend to fall on, the absolute earliest has been September 1st, while the latest has been the 17th, so assuming it's not later than the 17th, the 1st through the 17th are effectively fair game, that is, assuming that it's not past the 17th, which is something we can't say for certain on.
The last "Real" Nintendo Direct in September was the Mario one, which aired on September 3rd, and after that we had a Partner Showcase and a MH Direct on the 17th.
My "guess" is it'd be earlier than not, just to get some last minute advertising in for some upcoming games, but, who knows.