is posible to talk in a anonimus game? how is that posible?

i recently played a game without login and a player talk with me in the chat(he was a little mad for the lose and he started insulting me hard but it is not the question) how is that posible?

I've encountered this too. It used to be possible to chat anonymously years ago, so my best guess is that they have a very old version of the app which they have never updated, from when such chatting was possible. Just a guess though.