AMD has issued a statement saying that Chief Gaming Scientist Richard Huddy "misspoke" when he said earlier this month that DirectX 12 will not be supported in Windows 7. Huddy's statement was unequivocal—"DX12 is not coming to Windows 7"—but AMD says it was merely "speculative."
"Richard Huddy does not speak for Microsoft, and he was unfortunately speculating from Microsoft’s publication of key dates and milestones for Windows 7 lifecycle and mainstream support policy," AMD said in a statement sent to GameSpot. "Richard has no special insight into Microsoft’s Windows or DirectX roadmaps. Microsoft is a key, strategic partner for AMD and we’re continuously collaborating with them on DirectX 12."
DirectX 12 will be built into Windows 10 and Microsoft has previously confirmed that it will be compatible with Windows 8 as well, but it hasn't said anything about whether or not it will work with Windows 7. Despite AMD's disavowal, I think the greater surprise will be if it is compatible: Microsoft needs to pry users away from Windows 7—most of us are still using it—and has already announced that "mainstream support" for the OS will come to an end in January 2015.