Two years ago on 9/10, last year on 9/9 (labor day 1 week earlier) and this year 9/9 because labor day on 7th I agree with the rumor.
If that turns out to be correct, they'll go on sale on the 18th then instead of the 25th. That's the pattern that Apple has followed the last three straight years anyway as far as the turnaround time from the announcement to the release date (9-10 days).