Actually, this makes a lot of sense. Let's say you increase the voltage on your DRAM so that you can OC it. That means your DRAM is hotter than it would otherwise typically be. Then lets say that you run an algorithm that is hard on your DRAM , but doesn't tax the CPU all that much. You end up with an isolated hot-spot in your DRAM. Your CPU fan speed would still be slow due to the low load on the CPU. Your case fans might not have sped up very much because the total system temperature might not have gone up by much at all. But the additional heat from your DRAM could be enough to cause an instability.
Now lets say that the CPU fan controller is configured so that it knows there is a relationship between CPU fan speed and DRAM temperature. When this scenario happens, the CPU fan controller senses the increased local temperature of the DRAM, and spins up the CPU fan to help maintain system stability.
Similar concepts could probably apply to Vregs, chipsets, PCIe switches, Ethernet PHY chips, and other system components that typically don't have temperature management logic built-in. It wouldn't be the most noise-efficient way to keep such components adequately cooled, but it would probably be the most economical and would certainly be better than spinning available fans at max speed all the time.