Partially true and partially TOTALLY FALSE.
Yes, she would be back in play if Trump went away for some reason.
But no, she would not automatically "be the backup of choice." The majority/core of the pub party is MAGA and if Trump left the scene they would be looking for a replacement for him and not automatically default to Haley. They would still be looking for someone who is not Haley.
Don’t discount the million dollars she raised after New Hampshire. That pac money is power and employment for has beens.
Haley will have the second most delegates going into the convention. Don’t get me wrong we all know the MAGA types will go full tard and burn it down so there is that.