Sort of. At a certain threshold, everything is untested. I’d put this closer to modified than untested—the general config was tested in Artemis I and the specific configuration in a variety of ground tests.
If it fails and the mission fails with loss of life while knowing it went ahead despite the IG report about the heat shield... It might be the end of NASA.
Hopefully it will return safely.
If idiots and emotions rein, maybe. Then the centre of gravity for space exploration correctly shifts to Musk and China.
The problem is that the purpose of NASA's manned spaceflight program isn't to explore space. It's to make the President look good (and I'm not just talking about the current one here) and funnel money to contractors. In that respect it's doing quite well.