The /cwlinkshell command (alias: /cwl) still exists and when used will broadcast or change channel to your currently active cwls.

Quote Originally Posted by /? cwl
ALIASES:
　/cwlinkshell, /cwl
USAGE:
　/cwlinkshell [message]

→Sends a message to all members of your active cross-world linkshell, regardless of their location. Typing /cwlinkshell or /cwl without a message switches the default chat mode to your active cross-world linkshell channel.