"Maybe:" in front of Contacts on Message screen
This is a Siri Suggestion feature that can be toggled off at Settings > Contacts > Siri &amp; Search > toggle off "Find Contacts in Other Apps".

What is happening is that your device received a message or email from a number or address with a name that could be linked to it, e.g. an email from "John Smith " or a message from a new number that says something like "Hi, this is John Smith."