This isn't racism. This is demographics. Pick up Ebony Magazine and tell me how many advertisements feature white people, or asian people, or canadians... How many advertisements in 'Cosmo' feature men?
You try to make your advertisements reflect the culture of the people you are advertising to. Poland isn't exactly known for it's high black population. So they took an image and did a crap job removing a black person and swapping it with a white person rather than create another advertisement at a higher cost.
Now if every MS advertisement had <insert race / gender> removed, then yes, that would be racist.