Sure. But the ability to do this kind of rugpull is new and so you will get responses like these and that's perfectly logical regardless of the legalities. I'm not saying you can't. But I am saying that if you ignore your users - even if what you ship is free and open - you are still going to be subject to backlash if you change course very rapidly. You could also simply create a new project and support the old one during some transition period. Principle of least surprise and all that.