My understanding is that IGZO panels would save energy and reduce heat...
There is no guarantee that the next rMBP would have IGZO panels.
Especially if the MBA didn't come with those, the chances are very slim that the next rMBPs will have them unless Apple is playing favorites.
No one wants to buy older technology (let's be honest, the core components of the rMBP haven't changed since WWDC 2012) when newer models are just around the corner. Also, cMBPs were never on a strict 8-month cycle, and the current one hasn't seen an update in 16-months, though it might be discontinued mid-BTS like the white MacBook.
If by "around the corner", you mean "4 months from now" and "8 months from February" then... sure...
And cMBPs WERE on a strict 8-month release schedule since 2011. Let's take a look:
February 2011
October 2011
June 2012
February 2013
Coincidence? I think not.
The white MacBooks also lingered around for a long while before it was officially gone. My guess is that Apple has more stock of the cMBPs now so they're lingering around longer. But that's more incentive for them to push cMBPs away before releasing new rMBPs.
I agree that Apple wouldn't miss too many sales by launching in October, but it makes sense to launch now, when Haswell is ripe (most flagship PC laptops already have Haswell, e.g. Razer, Alienware, Sony). Obviously Amazon wouldn't buy cMBPs at a loss, but they could sell them off for a decent price on Apple's behalf.
Competitors don't have any pressure on Apple because they still haven't introduced anything that's close to the quality of a rMBP even with Haswell technology.
I mean... please point out another laptop with a 13" 2560 x 1600 IPS panel or a 15" 2880 x 1800 IPS panel on the market. Aside from the 13" Chromebook Pixel, which is very useless and costs almost as much as a 13" rMBP, there is really nothing out there that competes with the rMBP.
And you're forgetting the fact that if Amazon was to sell the cMBPs off for Apple, they'd want a cut of the pie as well. Their prices are already low enough that Apple would be getting back even lower than if they'd just throw those cMBPs on the refurb section instead. So economy comes in play here. Smart move: promote the living hell out of the cMBPs and offer discounts instead. Also make sure nothing can cannibalize that sale (like new rMBPs coming out and forcing current rMBPs to refurb at prices even lower than new cMBPs).
the only people who are ranting about how slow the refresh are those who wants the new MBP, include me

.
those who needed it would have purchased and went AWOL in this forum
Well ya. But what I mean is... all of this waiting could have been avoided and you could have just bought yourself a nice new rMBP months ago.
I know there were issues with the first batch (heck, I had my fair share), but you could always let Apple "fix" those issues with AppleCare instead of playing the "exchange" game. I had my display swapped for a Samsung one, and they somehow cleaned up the fan and cooling system for me, too. Mine is now nothing short of "perfect". To the point where I'd dread having to pick up a new Haswell rMBP only to find the same issues. There's no guarantee the next version would be perfect.