I feel like it wouldn't be that difficult to provide a surrogate mother to a newly... hatched? De-podded? Unextincted mammoth. Agreed on all other points. More scientists and engineers need to devote some brain power to the ethics of the things they are asked to do. There is a difference between ethics education in the sciences as a continuing education requirement and as something that is enforced in more than letter.
I suspect they'll use an Asian Elephant female as a surrogate. The problem is finding one that is pregnant or just had a baby, right at the precise moment the "mammoth" is born, and then the Asian elephant connecting with the mammoth baby, since elephants only have one baby like every 7 years, or something crazy like that. If she doesn't have the recent-birth hormones coursing though her, will she identify as the mother of the mammoth? And if she has recently given birth, can she mother two offspring at once? Or will they take away her "real" baby and hope she connects with the mammoth as hers? And what happens to the "real" baby...? It's ethical questions all the way down...