So, in the first place, a suggestion to do a localization of team mates / friends with hover on nickname. Too many times asked "where you are?", i think this is a possible solution. For example, a hover effect of the place where we friend is, like in this screen:
Some people simply do not want to disclose their location because sometimes they want to be alone or they are doing something they don't want anyone else (especially friends) to know, so this would be a complete invasion of privacy. If you want to know where your friend is, simply ask them and if they feel comfortable with you knowing where they are, they will tell you.