Could be true -- there's no way to know of course.
Well here's some evidence from the 1999 MacWorld conference:
"Apple's taken 'Just in time inventory' to a new level - while other PC vendors like Dell have 6-9 days inventory, Apple has it shaved down to 15 hours of inventory, 0.6 days."
That may not be quite the case now, but you can be sure it's not as long as 3 months. Here's a 2007 AppleInsider report in which someone comments that the turnaround rate is 7.3 days, based on 50.8 inventory "turns" during the year:
http://forums.appleinsider.com/showthread.php?s=&threadid=74961