The new Atlassian App Migration Platform (currently under development) will enable all Atlassian Marketplace Partners apps to build automated migration paths for their apps.
When a customer migrates projects from Jira Server / Data Center to Jira Cloud using the Jira Cloud Migration Assistant, the app migration platform will coordinate with Chat for Jira Service Management app to automatically move your conversations to Jira Cloud instance.
Currently, the Jira Cloud Migration Assistant can't be used to migrate Chat's conversations because of dependency on
MIG-133 . Please refer to our public documentation to learn more about migration process and the differences between Server/Cloud versions: https://confluence.spartez-software.com/display/CFSD/Chat+-+Server+to+Cloud+Migration