We have very much enjoyed the WHMCS Slack integration, but we are now moving to Microsoft Teams and would love to see an integration down the road.
Mainly, we use the integration with Slack to generate a WHMCS Activity stream. This allows our management team to review all staff and client responses to help drive customer service and training.
If not an integration, then simply a new WHMCS feature inside the software that allows for viewing all responses made by both staff and clients in a linear format.
Happy to expand on the idea and share our use case if others would find this of value.