so a new law making it required would likely solve the legal issues, and gets the dev team (the only ones thinking about users or doing what's right) get what they wanted from the start?
I doubt it. I don't think another law _reduces_ legal issues. If anything it makes the situation more complicated. The plug is still getting pulled and I don't think this materially changes the outcome. If the company shuts down I'm not sure there is a legal obligation to release the code or refund. What entity would be responsible for that work?