What is CASB's main purpose for Slack?
Is there any way we can create a policy that prevents CUT/PASTE content for Slack?
Stopping cut/paste would be a different tool.
Using gatelets, traffic to these services is inspected and acted on according to your policy configuration.
Kenneth, stopping cut/paste into the Slack application is possible using the Copy/Paste monitoring channels on the Endpoint Agent on the Symantec DLP endpoint agent.