Caledonian, ordinarily that would be true, but the point is that in the MWI the number of worlds increases exponentially as a function of entropy, so very soon high-entropy worlds outnumber low-entropy worlds by a factor of (if I'm not mistaken) ten-to-the-power-avogadrillions. As just one example, there should be a lot more Everett worlds where we used up all the fossil fuels than where we didn't. AFAIK that's still true if you consider only non-mangled worlds, but maybe I misunderstood the model and the number of non-mangled worlds actually stays constant under entropy increase.