Film Rights to First & Second Age

[William Cloud Hicklin]

No, they didn't in any real sense. "Published" is irrelevant, remember?

In any event, the synopsis in the Appendices does not purport to be 'The Silmarillion.' By its own terms,

Of these things the full tale, and much else concerning Elves and Men, is told in The Silmarillion

So, a prima facie declaration that The Silmarillion was a separate work with an independent existence- and moreover, one which everyone even dimly aware of Tolkien in the late 60s knew was supposed to be nearing completion.

It's still rather gobsmacking to consider the notion UA was so desperately concerned with a fillip tucked away on pp 1033-34, but made no move to acquire rights in the (independent) work to which it refers! It was right there in Tolken's office. You want De Niro? Here's This: UA wanted the Lord of the Rings. They didn't care about The Silmarillion.

You say:

an author sold film rights to something and then years later had it repackaged in a longer book length form

You make it sound like the first page of Appendix A was the purpose of UA's purchase!

But, seriously, folks: the 'book-length form' was of course not a 'repackaging' of the Appendix A (i) preface, but a 'repackaging' of many thousands of manuscript and typescript pages JRRT created over the course of sixty years.