Thats a bit rude. He could have advised you when you booked that he was going on holidays around your due date. Does you ob have another ob he works with?
I dont like the idea of being induced just because he is going on holidays. That just seems plain silly to me, but of course its up to you and your ob I suppose.
Maybe you could see another Ob? Are you ok with seeing him throughout your pregnancy then having another ob possibly deliver your bub?