the extra 100 TH1 had not been added yet - still waiting for next dividend to get mined. Bitfinex has always announced supply increases prospectively in this fashion.
That's really not enough time. Since most swap contracts are 30 days we should have 30 days notice before a change in supply. Otherwise we don't really know what we're buying or selling. It's now become a matter of speculating on whether or not bitfinex will intercede on the market, and when.