Azure Cloud tiering is most effective feature to provide extra fixability to the azure file share , with the help of cloud tiering unused or unassessed data stored on the local file server endpoint can directly ingest to the cloud with intelligent method. it is kind of data archiving solution. unlike other archiving solution where they replaced actual files in to shortcut same way  fingerprint will left for that particular files .when you need to access file it will download from contain in  azure cloud.

1. Least used content is cloud tiered
2. Before removing the files server from the file sync group make sure you pull down all data first otherwise you will loss data.  all data can be pull back with the help of PowerShell
3. File smaller than 64KB will never be cloud tiered, ,must be more that in size
4. Cloud tiering file server is server based not the sync group based
5. works based on the free space available on the file server endpoint

For More information :-

https://docs.microsoft.com/en-us/azure/storage/files/storage-sync-cloud-tiering