I don't know what he's planning, but it looks like he started the fee idea despite everyone's objections. I don't know how many people will agree to pay for this service but I know TW is a favorite social network for a lot of people even though people often complain that there are too many annoying bots on it. He is an extremely intelligent person, he is not a decision maker without careful calculation and now let's wait and see how people react to it.
Asides the authenticity of an account that verification provide, what other benefits does it provide? In the long run, this will lead to the loss of so many accounts. In the end, it won't be about the money, but about the benefit and unending payment. It would have been better to have an outright payment and a yearly price than a monthly one. There are other ways to earn money than this, especially through advertisements. He has not shown intelligence with this decision.