You got to understand that dx11_1 *bold* is what supported if you have DX11 cards. The _1 or _2 are increment updates via API softwares. As long as "dx11_*" is there means your hardware will support it from the ground.
The increment is new stuff, pretty much like any other software, Windows has their own build numbers but they instead say Windows Vista/7/8 because it is more friendly for consumer to understand.
If they name Windows 8.1.8000.2.3.4.14 for example, who the heck remember those numbers?
Windows 8 is 6.2
8 is like DX11
6.2 is like _1 or _2 (DX11_2)
If Microsoft release like DX12_0, that requires new hardware. As well the base dx11_1 _2 _3 _4 _5 _6. You're fine. In my common thinking, who the heck would make games only give out these features to like 0.1% population who will actually have a true 11.2 support? There is no advantage, it's just tiny API updates to improve the performance as we already see from Win 7 which is only limited to dx11 and it is not fully support dx11 anywho. Win 8 is truely dx11 supported and so on.
2 cents. I might be wrong but that's how I see it.