You misunderstood my comment. I said it felt out of place *here*, in a video dedicated to her mathematical work, hosted on mathunion.org (the clue is in the URL). Doesn't mean she cannot talk about the war in general.
As for Marie Curie, I don't think they had Internet and 24-hour news channels back then. I don't need mathematicians to bring attention to the war in Ukraine when everyone is constantly talking about it already.
By then the occupation of Poland had been going for more than a century, so it wasn't about news. And in case of Maryna it also doesn't seem to be about news. It is her well-deserved chance and her choice to say what she thinks is needed to be said on such a momentous occasion.
