The Conclave (a group that wants to stop humanity's expansion) was aware of the original position of Roanoke, and therefore was waiting to annihilate them. He further tells them that to isolate them fully, they are forbidden from using any advanced technology.
The Conclave (a group seeking to halt humanity's expansion) was aware of the original Roanoke position and thus waited to destroy them. He also informed them that to completely isolate them, they were prohibited from utilizing any advanced technology.