I don't get it. If someone gives you something that is vital for your product for free, and the license does not guarantee your free usage in perpetuity, and you can't take the source code and maintain things yourself if the vendor changes their mind, ... surely that's on you then? Did you think they didn't need to buy food and pay rent? To me as a complete outsider this move reeks of desperation on their part, not m…
For me, I just went back to doing web development. For someone in the indie game market, you either develop in Unity or cut yourself out of the employee pool.