What utter nonsense. Most of those miners will just switch their GPUs to different coins so no, there won't be a 0.2% in electricity reduction and I doubt that figure is that large to begin with anyway
Right. The power consumption depends on What Card you are mining on and what algorithm you are mining.
For Most of the AMD Cards, The most profitable algorithm is kawpaw at this moment which consumes 30.76% more electricity than Ethash.
So, If GPU miners move to kawpaw algorithm. It will increase the power consumption.