Google is generally good at returning correct results because they analyzed all users habits and can infer what one is looking for; it's up to the user to choose if it's worth the price to pay wrt privacy. As for Signal, it's pretty normal for search engines, whether they spy on users or not, to return the app, since in their algorithms an explicit name (Signal) always wins over a generic name (a signal), which imo is how a search engine should work. In due time, most searches for Element will eventually return the chat app. I'm not sure I will like the name by then though.