I think he did the right thing... she's hormonal, and she was making a bad decision in auditioning when she's pregnant like that.  Stress causes miscarriages all the time... and complications... and it's better for her health, and her child's, to just wait and try out next year.  (Let's say, by chance, she made it to the top 10... she would've been touring with an infant!  That's insane!)