If the infinity blade assets were claimed prior to the transfer, this would definitely be a bug, as I can confirm with a handful of other systems that they are still available in vault. Missing already claimed content shouldn’t be possible since it just accesses the old Marketplace to retrieve it.
If possible, could you make a report over here?
https://forums.unrealengine.com/tags/c/general/issues-bug-reporting-fab/211/unreal-engine