Oracle released Exadata X8 on 2nd Apr 2019 for more information visit https://www.oracle.com/engineered-systems/exadata/database-machine-x8/
New for Exadata X8, a third Exadata storage option has been introduced - the Exadata X8-2 Extended(XT) Storage Server. This storage type can be added to older exadata racks as well and exadata software is optional. So if you want to store huge amount of historical data where performace is not a concern XT storage servers will save lot of cost.
Regards,
Nishant