It means people will user Facebook messenger when they are not comfortable with the place they are in. If I'm at home, at my university or my cousins' I will chose Snapchat over Facebook messenger, because I'll feel free enough that I can talk and goof around with that app, in a way that is not possible with Facebook... yet! Also, I think there are people less boring than me who will not give a damn and will use Snapchat's Chat everyday, everywhere, and that's going to be awesome. As clichéd as it might sound, they really are changing the way we communicate.