OK, go and ask Intel for proof then. Because they just admitted it:
The only question that remains is if that "incorrect voltage" (which in my opinion qualifies as a "defect") was intentional, or an error. My guess is that their yields were not high enough for the high end parts, so they pushed the voltages a bit higher to be able to reach higher frequencies that they could not have achieved with safer voltages, so that they could sell even inferior silicon as high-end. Basically, I think that they gambled that nothing would go wrong by overvolting a bit, or that few people would be affected, and that gamble didn't pay off.
But, even assuming that they didn't intentionally do this, and it was just some kind of microcode bug causing the increased voltage, the problem now is that many of us have degraded CPUs that have been exposed to that excessive voltage for many months. That makes them unstable even with the current increased voltages, sometimes unusable without underclocking, and we have to manually reduce the peak frequencies to make them work properly. If Intel pushes a microcode update that reduces the voltages to safe levels, we'll probably have to reduce the peak frequency even further to keep them stable. Worst case, we might not be even able to reach the BIOS anymore to be able to underclock them.
In conclusion, I doubt the microcode update will make things more stable for those of us that are already affected by the degradation and stability issues. Possibly the other way around. But it will probably slow down the degradation, and fewer CPUs will degrade enough to become unstable, which is good news for those that currently do not experience the issues.