In this case, it does need an open letter. This was CS's way of laying out their case. Apparently there are others who think Classic Specs pulled shenanigans,

In this case, it does need an open letter. This was CS's way of laying out their case. Apparently there are others who think Classic Specs pulled shenanigans, and CS need to make their position clear to those people. Note that sending a letter to them directly doesn't expose the story to the rest of the world.