Micro four thirds - does the crop factor apply to MFT lenses as well?

That's incorrect! That would be true only crop factor was exactly 1.41X. In reality, Canon APS-C frame area is only 38% of FF, and Nikon is 43%.

That means difference in total light received between 4/3 and APS-C is only around 0,5 EV, not too much practical difference for everyday photography.