I'm afraid it's not the real reason. If they need to accommodate the meal cart, they would align the "3" seats more centrally, instead of keeping the same set of rail that is set for 4 seats in a row and just align all seats to the right. Why is it wide enough on the right hand side but not on the left?
Also, assuming your reasoning stands, wouldn't taking one row of G seats be enough rather than two?
If anything, it should be the C and H seats that should be taken away, not the random G