WWDC Hardware release history

Presuming they are announced at WWDC they might be available immediately. If so and you want one quick get yourself to an Apple store.

 

Little if anything that happened in the past is relevant to the Apple of today.

It's a real crap shoot.

 

They usually are "shipping" the day they are announced, but not available in stores. Online orders ship from China so they can take a while.

Shipping to store takes around 2 days. The 15" rMBP was announced on June 11th last year, and most Apple Stores started carrying it on the 13th (see this thread). A couple stores got them on the 12th and others got them later, so YMMV.

 

early has well might have some defective I would wait and see how other people say after they got it. I prefer Mid/Late model when Apple ironed out the defectives.

 

The "Post-Jobs" era has products getting released on different schedules and intervals. Remember last year with the 15" rMBP? Folks were waiting a month easy after ordering. They announced a new iMac and it was months before that came out. Look at the iPad releases. Very difficult to find for months. Tim Cook is very anxious to get products announced but availability at release has been sketchy at best. They have been getting so much worse at this now. Although it creates a frenzy which the marketing department loves, it causes some real short term frustration for customers. But Apple knows, those pissed off customers will return for again after they have forgotten how much of a pain in the ass it was to buy a new device.