I believe there also was some trouble with Intel's new speedstep technology they introduced with Skylake. The Microsoft Surface with Skylake suffered from poor battery life for months before an update was released, only for Win10 I believe. The new speedstep should allow faster steps in clock speed and power modes, which is overall nice, but MS probably didn't/couldn't fix that in the older Windows 7 architecture/kernels (or didn't bother).
Skylake PC's will just boot and work.. other than that probably not much to say. You probably should install Intel's latest microcode to fix some bugs. I see these support limitations as purely business/artificial driven, which is not unique to MS or the PC industry. As engineers/developers we probably all know how horrible it is to support patch changes in older/newer versions, maintain backwards compatibility, etc. Technically alot is possible, given enough time and resources, but MS won't make any money from it (new PC's will rarely be shipped with Windows 7) and want to push Win10 as hard as they can. So all in all it makes sense (for them).
Unless you want to utilize one of the latest connectivity options on Intel's platforms there is not much reason to upgrade since like Sandy/Ivy bridge age.
Some new standards like USB 3.1 and M.2 is nice. But honestly I have never 'needed' USB3.0 (USB2.0 does fine for my external harddrives etc.), and my current laptop came with a M.2 SSD which is also a bit quicker allround, but not worth the upgrade/extra cost/GB for me.
So only if you want to do a new system build I see it as a potential issue.