VMFS6: no File Level Restore (FLR)


VMX 7.0.1 gives me the following warning when it sees a VMFS6 datastore:

"You are Backing Up one or more Virtal Machines that are located on a VMFS6 Datastore.
You wil not be able to do File Level Restore (FLR). We recommend you to do an Incremental Backup."

Can someone shed some light on this? Notably:
1) Why is that? (What is the big difference between VMFS5 and 6 in that regard?)
2) Does it mean that performing incremental backups restores the ability to perform FLR?

Please advise.