It means a new building. And are you saying that if admitting a legacy kid or taking a restricted donation is net negative they shouldn’t do it? They just need to know in advance if the future donations from the family will be worth it? How simple!
Again if a gift will create a big long term financial obligation that will end up making it a net negative, it is obviously the role of leadership to choose whether to implement it or not.
Taking into account fictional future donations and communicating with donator and explaining the issue is called negotiation. Being convinced to make bad financial decisions in fear of losing a donator is again, a failure of leadership.
If someone offers you $10 if you spend $100 later you're better off not taking it, even if you could have bought something with that $10. That basic financial stewardship is the role of university leadership to deal with. They failed.