It's not less reasonable. They don't have to promise giving Bun time in the future to evaluate. They might do it but they absolutely don't have to be responsible for doing it when the project made such dramatic shift.
They can do absolutely what they want with their project especially when its majority decision. There can't be no doubt about that.
They can absolutely do what they want, and I can absolutely say it's an unreasonable decision. When I say "unreasonable", I am evaluating whether they are operating on sound technical principles or not - not like, "are they allowed to do this" or something more obviously true.