XFX have not pulled out, Nvidia aren't giving them any chips. No GFX board manufacturer in their right mind would choose not to sell GF100 based cards. These manufacturers are all locked in complex contracts and deals with ATI and Nvidia.
You do realise partners were selling 260GTX's for zero profit last year, when NVidia doesn't make profit, partners don't make profit. Nvidia will be taking a HUGE loss on these cards, you can bet your ass partners aren't making more than a handful of dollars at the most on these.
The reason not to sell them, you put your name on a card that no one can buy over the maybe 6-8 month period they are supposed to be on sale, frankly it will hurt your reputation. Or they can choose to make the single fastest graphics card around in an overclocked 5970x2, and be able to sell more of them than they would ever get 480gtx's, which is massively slower.
Why would you want to make a handful of cards, for no profit, and have you cards listed as out of stock worldwide for 8 months?
Wouldn't you want to be thought of as the company smart enough to ignore a pointless card that massively overpriced and be the company smart enough to jump to the best cards around, that are also available?
For the record, Nvidia most certainly won't be giving them priority, the same way Nvidia, Intel and AMD tend to give priority to companies for every launch, IE first tier mobo makers all got the first shipments of the SB750 southbridges and other mobo's with it came a lot later. Same with the SB850, Gigabyte and Asus are leading the pack by well, months basically with others to follow.
XFX could get chips eventually, assuming Nvidia plans on it being in production for more than an initial run which is questionable. Nvidia doesn't ignore sales, while it has very limited stock tier 1 and prefered customers would get them without a problem. They'll happily sell XFX anything they have in stock, it looks better for XFX to say they don't want to make them, than wait 2 months extra for a handful of cards they can't sell at a profit. Its definately their decision to never make one though.
If EVGA went to AMD and asked for chips to make a 5970, AMD would say certainly, without doubt, you're welcome to give us money, but you'll be last on the list to get stock when its available. No one turns down orders.