Because she is not his property, neither are her pregnancies.
Because she is not his property, he is not responsible for maintaining her. She is responsible for tending for her own wants and needs.
Subsequently, terminating her pregnancy did not breach their contract. He can choose to separate from her, but he still owes her the remainder of her education an the financial support required for her to complete it.
The "currency" she was "paying" with in the "contract" was a loving relationship based on mutual trust and appreciation. She violated his trust. No trust, no relationship, no financial support.
She has a right to cheat on him, she has a right to talk shit about him to his mother, she has a right to make fun of his small penis. He doesn't own her, after all. But that unquestionably violates their relationship, and therefore their contract. So does an abortion without having a discussion about it.
That's what a relationship is. Anyone can set whatever ridiculous rules on the relationship they want, from "you can't have abortions" to "you have to put the toilet set down" to "we're converting to Scientology". And on the flipside, anyone can walk out the door at any time, and all the benefits and burdens of putting up with your shit walks out the door with you.
She's a woman. She is a real person who makes real decisions with real autonomy and real agency. She isn't an infant that needs to be protected from herself and sheltered from the big bad world.