The audience would be wondering "Why are we spending time on these characters?"

While the inclusion of the Pevensies in LB might be a little challenging, especially with all of the years stretching in between the Walden Trilogy and the upcoming films, I also think that they're necessary glue for the story.

1. How would the Friends of Narnia have even formed without the Pevensies? They're the ones who know Digory Kirke. You'd at least need to mention them for exposition purposes, and if you say that much, then you also need to explain why they aren't around anymore... "they all moved abroad" and thus missed out on the exciting conclusion to a world in which they were pivotal players feels weak to me. That doesn't feel like a creative decision; it feels like the sort of thing that happens when a production team can't get the actors to reprise their roles.

Further, I think it could be a good idea to go ahead and introduce the Friends of Narnia in MN and HHB. While I admit that having each movie begin with "story time" at a Friends of Narnia meeting runs the risk of being a little hokey, I think a thread to tie the films together might be in order. The remaining four stories don't exactly fit together as a cohesive series. Here, meet Jill and Eustace! Now meet Digory and Polly! Oh wait, it's time to get to know Shasta and Aravis! And now back to Jill and Eustace! It's pretty atypical for Hollywood, to say the least. Friends of Narnia scenes in MN and HHB could help provide more of a narrative, and the audience would already know what the Friends of Narnia are when we see them in LB.

2. I've known fans who have listed HHB as their least favorite book because it felt like too much of an outlier in the series. I myself have worried in years past that they might find a way to reschedule the events of HHB so they take place right before LB, making the events of HHB more immediately relevant and allowing Aravis and Shasta (who will probably be popular characters) to be included in LB. While I don't think that the Estate is likely to let that happen at this point, it remains that HHB doesn't have a strong link to the rest of the stories that are left to be told. Calormene aggression is a thematic link and an important one, but it's only in the abstract. Bad blood between countries is just a concept, but the Pevensies are real people that the audience can establish familiarity with. I think HHB would feel more connected to the last four films as a whole if the Pevensies are also included in LB.

(Sorry to go a bit off-topic.... )

Can't say what would be best from a movie point of view--I do know that I would be terribly disappointed if they left the Pevensies out of future films. They might only appear in miniscule cameos (though I can think of ways that that could be improved) and should be the original actors (which might be hard, viz., cost/availability issues).

As to Susan, I don't think they ought to whitewash what happens with her. It needn't be a large part of the story; indeed, it is merely an aside in the book itself. My initial response on reading that section (and for many years) was more or less, "Oh, too bad about Susan," and no more than that. If the movie makers choose to make a big deal of it, and say that she was condemned to hell because of boys and the like, I would strongly disagree. That is the conclusion of other people, not Lewis.

Hollywood doesn't seem inclined to avoid bringing up inflammatory ideas (when sometimes they should), so I don't see why they would shy away from including some reference to Susan's disillusionment. It really does depend on how much they bring in all the rest. If they decided to scrub further appearances of the Pevensies, then by all means leave out Susan's lapse. But really, I would rather have it in there.

The Pevensies are nowhere in the Silver Chair either. Eustace makes a passing reference to "my cousins" one time. That's as close as they come. HHB is the only opportunity that audiences have prior to LB to get to know any of the Pevensies

.

Not as much as you think they should have been, to be sure. The Pevensies may be no more than a memory in Silver Chair, but they were most likely at the party at the end of that book, when Jill wore her Narnian Costume. Parties are often held for homecomings as well as for other reasons, and the other three Pevensies would have lapped it all up and enjoyed Jill's gesture as they were introduced to her. But if Susan was there, it would have been so typical of her to behave like a wet blanket, acting as if she was "grown up", especially if she expected to be the centre of attention and also had other fish to fry in her life.

Besides, more than one comment I've seen drew a strong connection between The Queen of Underland's rather long speech to Eustace and friends in the eponymous chapter, and Eustace's comment about Susan in LB:

And look how you can put nothing into your make-believe world without copying from the real world, this world of mine, which is the only world. But even you children are too old for such play.... Put away these childish tricks. I have work for you all in the real world.....

Eustace said in LB:
"...whenever you've tried to get her to come and talk about Narnia or do anything about Narnia, she says, 'What wonderful memories you have! Fancy your still thinking about all those funny games we used to play as children' ".

LB is all about work. Work to satisfy the Calormenes and a fictitious deity called Tashlan. In HHB we learn that the Calormenes regarded the Narnians as idle and unprofitable, whilst Queen Susan's looks mattered not at all, despite what she might have thought.

Education is a process, which relies on memory and experience of what we and other people do and how we interact as much as it is about training for careers and qualifications, gained by how well we remember and apply of what teachers try to tell us and illustrate to us. This is a strong theme of both LB and SC. It is just as true of HHB, PC, MN and even VDT.

Aravis and Shasta are in LB, in the "real Narnia" of memory and children's literature. It is likely Queen Susan's denial of her Rabadash experience, and her agreement with both Calormene attitudes and LOTGK which also bundles them together in LB, and which ties her to what she now thinks is the "real world" of adulthood, socialising and "romance". That is why Aunt Polly cannot accept Susan's interpretation of adulthood. Because all of life, while we are alive, is about our memories, our experiences, what we do, how we play and interact with each other, what ethics we adopt and how we grow up by processing all of these in what we understand to be "our world".

I've no problem if Queen Susan is left out of LB altogether, but a nasty look and comment from the homecoming Real world girl, the centre of that party at the end of SC, perhaps showing off to her family about her American adventures, might well enhance that story as well, or more so than in LB.