I've seen posts that were calling for violence (usually directed against those directly involved, or leadership, which is natural given the circumstances), but I have not seen anyone (with significant upvotes) calling for genocide. If "any post about Ukraine" has this content, I'm sure it will be easy for you to link a handful of examples?

Show me one single post about Ukraine where a top 3 voted comment is “screaming about genocide against Russia”. I will save you the time, don’t bother, because it doesn’t exist.