Sounds like a spaghetti monster, but that sentence is phrased kind of backward. The idea is that IF we are likely to become posthuman, and run simulations of ourselves, then the humans in those simulations are likely to do the same, and so on, until there is a large number of simulations. In that case, the probability of us being the very first simulators is very small, so we are almost certainly living in one of the simulations. So I think the point of the above statement is that you can't believe we are likely to become posthumans capable of simulating ourselves, unless you also believe we are almost certainly in a simulation. Not saying there is any evidence either way, but neither is the quoted statement. It's not really a speghetti monster, more of a statement of the constraints of belief in such a speghetti monster.