That seems a bit "stalkerish". That was a criticism of the real SnapChat map, and it probably would be a criticism of this feature too. Granted, features like "ghost mode" could be added to it, but in general I really don't think this is needed; especially with a game with a lot of younger kids playing.
Also, in order to do this, you would need to "add friends", which means having a chat system, which leads to putting more younger kids at risk with talking to strangers, being lured to locations, etc.
There is a difference between a social media app for teens vs. a mobile game app that kids can play. If you look on Google Play, you'll notice that SnapChat is rated "T" for Teen and Pokemon Go is "E" for everyone.