I think there have been several people who have been erased from photos. I recall one photo that had been updated several times to remove more and more people until only 2 were left.
That's another example, but not the one I was thinking of. I clearly remember the photo, and yet it seems impossible to find on the internet. Closest thing I could find is this one, but it's Mao instead of Stalin: https://11points.com/wp-content/uploads/2011/11/maofuneral.j...
Trotsky was indeed deleted from a couple of pics, but they are much more obscure.