To call the big bang tho the end or the beginning of the universe is scientifically incorrect since it does nothing else than putting symbolism in a thing that doesnt care about symbolism. The same it with God and since I dont believe in God, I dont believe in symbolism as well
Plus there is the fact that we have natural constants, like the gravitational constant or the Planck constant. Those have very asymmetrical values and seem somehow to have been set ( no not by God ). There values are increasingly important to our existance cause if the gravitation would be just slightly off our whole solar system would have evolved differently or not at all.
Therefore scientists think that the big bang and following up crunch actually happened a couple of million times before our universe as we know it formed. So even the symbolism of the big bang being the beginning would be off here