Dis na confam move by GTB. Even though e de one sided (as naira to dollar conversion option never de), e still fit bring benefits like reduction of fake dollars in circulation...
This matter no concern controlling fake dollar in circulation because wetin GTB dey convert na Dollar to Naira, and the transaction they happen online, you go send your dollar to them and dey go give you naira. If you check am well like this how e go take reduce fake dollar in circulation when na Naira dem dey give you and you no go fit send dem fake dollar online.

my broda no be small, e good as you really clearify this point because me sef be wan ask same question because as I see this post and as I read am finish, I understand say the op made mention of online transaction exchange concerning your dollar and naira wey GTbank dem self go send for you and with what I understood, dem no dey actually send you dollar and more over its online so I doubt the possibility of fake dollar online.