There is no unknown. Decklists are public and if there is a line that gets a better result, it's taken.
As others are saying, Cabal Therapy is busted in this narrow format, so it'll be out with Thoughtseize and Blackmail.
Gotcha. I would argue that due to perfect information Therapy is definitely a ban-worthy card then. Format isn't really blind then, amiright?
Brainstorm Realist
I close my eyes and sink within myself, relive the gift of precious memories, in need of a fix called innocence. - Chuck Shuldiner