If I am not wrong theymos doesn't need anymore revenue via advertising for development of the forum he already has more than enough in the reserve so he just thought no more ad slots which actually should increased the campaign via signature and it happened too via mixers by increasing payout rate more than others now they are no longer allowed here for advertising the dynamics have changed.
I mean, think about it for a moment. If there's more than enough in the reserve, then why not just give up those weekly slots to Open source non-profit Bitcoin projects and service?
Maybe advertise Electrum, Bitcoin core, The new forum software etc