As you say, it was all just math on paper until we actually saw it. This may eventually overturn the idea that the universe began from a cosmic singularity, we don’t know yet. One interesting thing they have found however, is just at the extreme edge of what JWST is capable of seeing: little red dots—LRD’s. Red because they’re extremely red-shifted, therefore very old. They’re as bright as galaxies but they’re not galaxies. Progenitor supermassive black holes perhaps. In any case there was something there before anything was supposed to be. So our theories about the very early universe are in fact broken.
It may be that something as basic as the red shift theory is itself broken—though I admit I do not know how exactly.