It reminds me of the 8800GTS-9800GTX iirc, they were essentialy the same cards but with a small rehash.
Have AMD swapped building with Nvidia?
Well it's different because the 9800GTX wasn't an OEM part, it was in the retail channel.
It's the G92 GPU basically, which was in the 8800GT, 8800GTS 512MB, 9800GTX, and the GTS250.
Which were all retail parts available for people to buy. So some people really did buy a 9800GTX thinking it was a big upgrade on an 8800 series card.
The onus should have been on them to know what they were buying of course, but still it's not the same situation.