I thought I'd heard they'd already made changes to the heat shield after the last failure. Hopefully whatever they learn from this trip will be useful for their next one.

So they made a first real test with Artemis I, and it was deemed unsafe because of the heat shield. So they modified the heat shield and didn't bother making a real test with it. "Move fast and break things", I guess?

Sure, they tested it on the ground. But that's what they did for Artemis I, and we know how successful that was.