Well, I think it was a very unfair thing for him to have done. He should have talked to you about it first, so that you would be prepared for the fall out, at home with your DD. He should have talked to you, about the best way to tell her also. As it is you that will be there to comfort her, and you that will be with her full time in 5 years time. Its a very log time in advance to be telling her, especially as its seemingly not set in stone.
A really callus, selfish thing for him to have done. Also, to mention that if he had other children wh might not go, does not exactly instill a sense of her importance to him! It makes it sound like 'you are not important enough to stay here for, but my 'new' childrens needs will be more important and considered more than yours"
I'd be very angry if I were in your position. I really think you need to talk to him about it, and make him realise the impact this has had on your DD, and it would have been courteous and respectful to have given you prior warning, so at least you could have been armed with possible answers to any questions she might ask!
Don't let it lie either, as it will not go away now, and this needs to be addressed for your Dd's sake more than anything. Typical bloody selfish man. ( ok apologies to any lovely men who are not selfish... I know there are some of you out there )