Why? As long as the fake numbers in the bank accounts don't leave the "system" does it really matter?
(to be fair, all money is fake but only governments have the power to enforce the value of their fake money)
But, does it matter? If people inside Lebanon could still transact with the "fake" amounts with bank wires and card payments and whatnot, the illusion would work as long as no interaction with the external world (International wires, and cash transactions)