For those unfamiliar with QTI, it's a simple simultaneous test of many-worlds plus a particular interpretation of anthropic observer-selection effects: You put a gun to your head and wire up the trigger to a quantum coinflipper. After flipping a million coins, if the gun still hasn't gone off, you can be pretty sure of the simultaneous truth of MWI+QTI.

Wouldn't any of several multiverse theories predict the survival outcome, and therefore you can't conclude that the quantum MWI is correct? That is, a world which is single, yet contains you infinitely many times due to being spatially infinite, will also "collapse" every so often and let you survive. Or the simulation masters could be selectively manipulating the quantum events to make people who do weird experiments like this survive (no, I don't think this is likely at all).

Why would observing your own survival make you extremely confident of quantum MWI as opposed to other multiverse or savior theories?