Well, except no for several reasons. You've been given citations to show that American media are using the name Kyrill, at least in some cases. Again, I just don't think we know yet what the right name for this article will turn out to be. There's no need to rename it without knowing that. I refer to this, especially the part that says: When choosing a name for a page ask yourself: What word would the average user of the Wikipedia put into the search engine? At this point, we simply do not know the answer to that question, and there is no point in renaming the article until we do.