This problem analyzer helps with the deletion of flows in API version 44 and above. In order to delete a flow in Salesforce using this API version, you must list every version of the flow in the target environment.
What triggers this problem analyzer?
If your deployment contains at least 1 flow deletion and you are using API version 44 or above, you'll see a message from Gearset stating "In order to delete a flow from the target, all versions must be removed"
What problem is it solving?
If you try to delete the flow without referencing all versions, you will get a deployment error from Salesforce with the message "Insufficient access rights on cross-reference id". This will only happen in API version 44 and above.
A workaround without this problem analyzer is to do the deletion with API version 43 or below.
How does it work?
Gearset will check the flow versions that exist in your target organization. If it detects that any flows are being deleted, will replace the unversioned deletion with all the versioned flows that exist in the target.