Unless there is an unsupported special character or the name is too long, the chat name should be your Steam nickname, otherwise it switches to a numbered Commander or DMGAME.
There should eventually be an option to request a specific name, or it be based on your PlayerProfile name, or something. The non-Steam versions are not going to be able to use the Steam nickname.
I hope it's not eventually playerprofile names, or people are going to show up in chat as
"My PITA little brother's multiplayer jam session with his dorky friends - do not erase!".
