They can fork tailwind into openwind and keep using the stable version for a looong time with minor fixes.
And that would probably benefit shadcn somewhat since they would have more control.
It would be in their best interest to keep "openwind" stable since changes to the CSS lib would require extra work in their component.
Different incentives.
Is keeping both stable in their best interest or yours?
The set of options includes choosing to not keep anything stable. They can abandon both and go do other things. If the market wants them to keep x alive, it can offer a premium.
Because to me Tailwind maintenance look like a 2 devs jobs at best.
They have 3 founders. They don't even need to hire.