There is a lot of misunderstanding about the requirement of falsifiability. At root it is simply the idea that an empirical law is not a logical tautology. I don’t see any reason to dispense with that just yet. In practice the principle affords us leverage only when we have two or more theories competing to describe the same domain.
Another thing that needs to be understood is that no reasoning from Bayes’ theorem nor any inference from probabilities has anything to do with the initial abduction, which takes us from a state of unquantifiable uncertainty to the first hypothesis of a conceptual framework, model category, or reference class. It is only after these choices are made that speaking of probabilities becomes possible.