You arenβt losing 25% profit. The cost of your Unity Enterprise license that you pay once each year would increase by 25%. For ease of understanding, if your license previously cost you $100, now it would cost you $125. However, Unity has stated that this is negotiable and does not have a fixed price. It is possible that this price is calculated with many variable including number of employees that use Unity (seats), yearly revenue and expenses, and potentially other factors as well.
And again, for Unity Enterprise you would need to make a Unity game that makes more than $25 million per year.