Above document mentions a Direct Migration mechanism from NetBackup CloudCatalyst to MSDP Cloud, which will be available in a future NetBackup release.
It also mentions that the NetBackup server upgrades to 9.0 and later releases are not supported for CloudCatalyst servers. Also, as mentioned in NetBackup 9.0 Deduplication guide, Cloud Catalyst section has removed from NetBackup 9.1 Deduplication guide.
However, the above document is not updated recently. Appreciate if someone can help me with the information related to "NetBackup CloudCatalyst to MSDP Cloud Direct Migration" mechanism, If it is available now, or in which release it might be available.
This process (direct migration) is supported in NetBackup 10.0 and above. The process itself is detailed in one of the appendices in the Deduplication Guide with the required prerequisites, process to migrate and post migration steps.
So the process has been available since March 2022 - although you have to upgrade to 10.0 to use it.