Gas Powered Games has teased at some upcoming content for Supreme Commander 2.
In RTS's most recent update, which added fixes and balance changes, a new option popped up called, "No DLC units".
When asked about the feature, a GPG staffer said on the Steam forums: "It's a secret! (At least until it's not a secret.)"
Sounds like it won't be a secret for much longer.
Thanks, Big Download.