Lately it has been the norm for Mac hardware, yes. Unless it's a press-release spec bump, redesigns of Mac products are generally not available right when they're announced. MacBook, Retina MacBook Pro, and new Mac Pro all had decent wait times from announced > shipping. Only recent exception I can think of is the 27" iMac 5K and the 21" iMac 4K.
Also let's not forget Apple would likely open pre-orders (or give a date for them) if they got announced tomorrow with a shipping date in October, so it's not exactly like they'd be losing out on sales for a month, it'd just be deferred. The "Apple will lose a month of sales" reasoning is a bit weak, IMO.
Guess we'll find out soon enough