If it is grounded without a specified end time, isn't it grounded indefinitely?
The launch license was for only 1 launch. They need to get another one to launch again, which will take an indeterminate amount of time, and isn't technically guaranteed to ever be granted.
The Artemis program could also be cancelled by politicians and budgets
There seems to be a lot of things that went wrong in this launch, and the FAA will want to see those issues investigated, from engine failures at launch, to the disintegrating launchpad, all the way to a possible malfunction of the flight termination system, because it seems the rocket disassembled itself before the FTS could do its job in a controlled way.