So do you think he increased allocation to more active merit sources perhaps and decreased allocation to the less active ones?

Theymos will probably stay silent like the invisible hand of Adam Smith that moves the merit economy, so I'm guessing that's what he did.  I too am curious about who the new merit sources are.  I suppose if they don't reveal themselves, they'll eventually get outed in that thread that does it mathematically.  I forget where that thread is, so I can't link to it at the moment.