Of course, the classical definition of "science" is more expansive, including what would be the most general science - metaphysics - so in that sense, yes, you can say the existence of God is a "scientific fact". (God here is self-subsisting being, not some ridiculous "sky fairy" straw man of New Atheist imagination.)
Change is not presupposed by science. Various experiences/models of change are described by science, which is not the same thing at all.
There are block universe interpretations of cosmology which do not require change.
If you redefine God to mean "fundamental assumptions of the universe", its existence becomes tautological. But that is not what most people mean (including the author of the article we're commenting on) when they say "God".