But the conversation isn't about authorization others to have creative control over his work. It is about intent on how others would adapt his works.
No one is arguing whether Tolkien authorized film companies to adapt the second age - we know that this is the case because the 2nd Age is covered in the appendices and that is part of the rights. Whether or not he INTENDED the second age to be adapted is completely different from this, because intent is not authorization.
Just like if I hand over the keys to a friend to watch over my apartment for the weekend while I'm out on vacation, it does not mean I intended him to throw parties and trash the place and leave it in a state of disrepair by the time I get back. Authorization is not Intent. You could argue that I'm taking the risk, you could argue that I'm responsible for the decision to give authorization, but you can't draw a conclusion that I would be okay with the fact that the apartment got trashed just because I took the risk that it could potentially happen. You can't argue that 'because you authorized it, that means you're fine with the result'. That's not what IC was talking about.
And again, for that matter, IC is also applying the same fallacies of implying that Tolkien would have openly opposed the 2nd Age being adapted, because no one actually knows how this theoretical situation actually plays out. No film company ever expressed wanting to do such a thing while Tolkien was alive.