Please tell me specifically what makes this qualify as news. Will you now publish every anniversary from around the world?

No, but this one is important because there are people on here who want to deny these massacres ever happened. Also, it's an ongoing controversy.

Or are you just another person trying to antagonize Poles and Ukrainians? Because it clearly looks like the latter.

That's kind of a strange perspective, isn't it? If someone made a post about the anniversary of, say, The Trail of Tears for example, then I, as an American, would not be offended in the slightest. If I made a post about the Nazi German invasion of Poland, would you say I was "trying to antagonize Germans and Poles?"

Here’s another suggestion perfect for future anniversaries you could commemorate:

Whataboutism.