Brother, you may be right as I am also afraid of the fact that the paint may start scratching after some time but I have checked it many times and I think that AHL has introduced it after research like AHL when introduced the Silencer in HONDA Delux 125 and then in CG 125, at that time people thought that the black paint would not work good but it works good and now they have introduced it in PRIDOR too.
One thing that I would like to share about black side covers of engine is that AHL may have made this decision after the sale of milloions of bike due to the following factors:
1- Every one has observed that in every product of AHL, on the left side of motorcycles, there is battery and when a bike is used more then the battery acid drops on the side cover of engine which destroyes the surface of left engine cover alongwith chain cover.
2- Due to oil leakage in any AHL bike.
Therefore, in my view its a good step as when the color faints or scratched then you may get repaint it and your bike will remain new.