I've undeleted the room, so it'll be viewable until the deletion script next runs. (At any time, feel free to raise a flag on Stack Exchange, and a moderator will undelete the chat room for you.) There's not a way to stop Stack Exchange chat automatically deleting rooms, other than filling the rooms with enough dummy messages. It's a longstanding feature request: https://meta.stackexchange.com/q/288612/308065.
