It's a tough one. I'm typing this sitting in an Eames knock-off (though the Italian factory claims they have the license since they used to do the European manufacturing)
I think the new UK copyright law would trump any licensing agreement. Knock offs will need to make obvious changes to existing designs to circumvent the 2016 law change... those changes are likely to compromise the integrity of the design/object.
It's a tough one. I'm typing this sitting in an Eames knock-off (though the Italian factory claims they have the license since they used to do the European manufacturing)