“our theories of early galaxy formation may be wrong”
That means the Big Bang is total garbage—which many of us have suspected for a long time.
That means the age of the universe is completely unknown—all previous estimates can be tossed in the trash.
This has nothing to do with the Big Bang theory. The universe is expanding; we have direct observational evidence of that. All this means is that the early period of the universe, which we are just seeing now, might not match our theories.