is there any substitute/workaround to PLAY_FILE ClientCom command but in Communication Panel? I mean this function:
Or maybe is it on a roadmap to implement such a function in Communication Panel as an Action type message?
Currently we don't have such a feature for Communication Panel. On roadmap we have item to enable automatic agent greeting out of the box. In short this feature would enable agent to record greetings and configure what queues should play the greeting.
In CDT world, like you said the same can be done with clientcom and partners have developed custom code/solutions around it. With Communication Panel the audio stream is webrtc and more difficult to be injected. I know that a partner is trying to do it for onprem Communication Panel release, but don't know current status.