After logging into Beta on a Silver 18/20 account there is an option to order TDS. Clicking this option takes you to https://www.everquest.com/expansion-content that offers you the ability to order The Call of the Forsaken. NOT TDS.
Sounds like they updated the beta server to offer TDS even tho it won't be available for sale until the 28th. Or Oct 11th for your silver account.
I just tried with a Gold 20/20 expansion account and the same option happens: https://www.everquest.com/expansion-content I guess they need to BETA test the BETA test log in screen :^)
