That just moves the problem to the definition of “metaphysical”. If a scientific theory is falsifiable, by what definition can it be considered metaphysical?
when a theory makes claims about events that fall outside of the physical system they become metaphysical:
age of the universe,
creator or not,
teleology,
interpretations of probability,
primacy of logic (are we allowing for the law of excluding middle or not)
Science doesn't do these things but scientism does.
