Halving being nearby has nothing to do with the number of posts people make in a day. There might be a thread about it, but I don't think it's enough to keep the number of monthly and daily posts of all members increasing.
I think he is referring to bitcoin price that went up and halving can further push the price up. There have been more traffic on this forum when bitcoin price increased in the past.
Stop of campaigns that pay per posts like Chip Mixer and other mixers are main reasons if I am not wrong.
Chipmixer has been banned which opened ways to other mixers on this forum and the competition was high among them. They pay more than other campaigns. The mixers are even paying for avatar campaign also. This encourage more people to join campaign and post. Mixers campaign ban on this forum is the reason.
The forum has allowed millions of dollars in signature income to be earned.
The income went down and the signatures went down.