What are the best practices to migrate workitems say PBIs/Features manually from TFS to VSTS? And how to ensure we don't lose any linking to changesets or other linked child workitems?
Have referred the below link and the migration tool mentioned is deprecated and would like to know any other options which will help to migrate the data.
How to migrate work items from TFS to VS Team Services (VS Online)
The recommend way for now is using Migrate to Visual Studio Team Service, a way import your TFS Database into Visual Studio Team Services which definitely along with data.
However, currently only the following versions of TFS are supported for import with this tool:
You may have to upgrade your TFS server to use. Alternative, the Microsoft official option is using public API-based tools.
Personally, even though Team Foundation Server Integration Tools has been deprecated. You could still use this solution in your case.
Besides, if you have no work item customization, then OpsHub is an option. VSTS Sync Migration Tools is another way. But none offer a full fidelity migrations. Each tool has its own limitations.