It’s an AYLOR question. Some rabbanim who say not to commemorate say you should stop if you are in public place.
Hashem wants us to be happy, we have a mitzvah to do that every day. Holocaust day is no exception, and we have no reason to be sad or commemorate anything. It’s more about the sirens which is a goyish concept. Why does the government need to tell me how I should commemorate the holocaust? I’ll do what I want in my own way.