I think you're suffering from a form of justification bias. That sounds like something out of a dystopian sci fi.

Here's the MUCH more realistic scenario that makes his contract unethical:

• Scientists try to introduce mutation into embryo

• Mother for whatever reason decides she doesn't want to have the embryo implanted.

• Who knows, maybe they can't afford kids. Or her and the father are about to break up. Or she has found out she's at risk of complications.

• Or maybe they overhear that the experiment didn't go as planned and the mutation is useless or possibly harmful.

Anyway if they say no they're suddenly in debt millions of yuan.

Implanting an embryo into a person under those conditions would be coercion.