The hardware supports it. The specs are open. But they don't have to take responsibility for any patch that rolls their way. When you accept a patch like this,

The hardware supports it. The specs are open. But they don't have to take responsibility for any patch that rolls their way. When you accept a patch like this, that means you have to be responsible for fixing it if it breaks. If Ubuntu wants to make their own window manager separate from everyone else, they can maintain their own Intel driver patches too.