Well, yes, but that will break the ceteris paribus for the anthropics.

I'd rather just see it as a different way of mathematically describing the same thing. Greatly simplifying, you can either have a law of X=Y or you can have plurality of solutions inclusive of one with X=Y and an unstable condition where when X!=Y everyone's twins "die". In a sense that's merely two different ways of writing down exact same thing. It might be easier to express gravitation as survivor bias, that would make us use such formalism, but otherwise, the choice is arbitrary. Also, depending to how vacuum decay is triggered, one can obtain, effectively, an objective collapse theory.

With regards to probabilities, your continued existence constitutes incredibly strong evidence that the relevant 'probability' does not dramatically decrease over time.