We aren’t looking at those old galaxies today. Due to the speed of light and the vast distance involved we are looking at the light from those galaxies when they were very young and early in the life of the universe (that’s why we are looking there in the first place). That light is just now reaching us. We have theorized about white holes but never seen one. By looking at closer objects we already know what an old galaxy looks like. And nothing can by definition exist before the big bang. Because before the big bang there wasn’t any space for things to exist in. Nothing precedes it.