Demesnedenoir
Myth Weaver
I think this is where the internet can do wonders for the reader who wants deeper info into the world. The novel itself should be tight, nothing that mucks up the clean story (too many writers plop down would building diseased words all over), but having a website that is more than about self-promotion "ME! The author! Look at me!" where you can layout cut chapters, historical short stories, character backgrounds, maps, etc., is just a wonderful opportunity for fans to geek out. That's my goal with my website. By reading book one, you won't know what a Maimer or Mercy is... but if you want additional info, it's on my website. Now in book 2, I get to talk about the Maimers and the Mercies because it makes sense to fill it that blank in the history at that point. How did the MC end up where the story begins? Sure the book gives it a quick necessary pass, but a short story will answer the questions in detail that wouldn't make sense to stick in the novel/prologue.
Right. But the foreshadowing (or perhaps side-shadowing?) is indeed there! With Tolkien, as with the Bible, you really need to read his four novels with authoritative guidance: the HoME and the Appendices by your side ready for consultation. Perhaps even a copy of Letters! There are a lot of things about Ents and Tom Bombadil and Pukel Men (and even Numenoreans and the Men of the North) that become much clearer after reading further than the actual story.
That's a lot of worldbuilding! While a reader does not need to delve into the histories of Men of earlier ages to enjoy the story, all that is there for those that do, and I think it will enrich the experience. I've read loads of fantasy over the years, and have often wished the author would have cared enough for the worldbuilding aspect of her craft enough to immerse me all the further into the experience.