There's no spoilers in my post. I guarantee that you could precis the entire series of books in a post and not give away anything that will be in the series.
As to gender swapping major characters - what's the point? Other than as a box-ticking exercise to keep a certain segment happy and on board, there is no point. If (God forbid) they decide or are allowed to *ahem* 'adapt' any of the other related books, i.e. the Elijah Bailey novels, they'll find they've painted themselves into a corner. It is, actually, a Big Deal. If Daneel/Demerzel is female, then his designer must have been female. So Jander must also have been female, so Gladia must now be male (or gay) so Elijah must now either be female (or gay) and it gets worse and worse! And to what end?
Try doing a gender-swapped version of Anna Karenina, or Madame Bovary and see how that goes.
Anyway, the whole gender swap thing has been done to death already - we got it, male -> female character, new insight, inclusive, fresh, modern, bold, daring etc. etc. except that it isn't any more. It's become expected, and is just a lazy, meaningless sop. The only thing that'll be missing is zombies, and I'm not so sure about that...
Poor adaptation? Going by what we already know, it certainly is, though 'adaptation' is stretching it a bit, when they add in huge swathes of content not in the books and feel free to take a perfectly decent story and turn it into something simpler and more understandable for a modern audience (read: dumb it down to the point that it becomes indistinguishable from everything else, and cloak it in fabulously expensive design and graphics and hope no-one notices).
So this is what happens when the superhero movie crowd get their hands on something. Superhero movies are by their nature simplistic, immature and infantilising, so it's hardly surprising if they continue to churn out more of the same. It's a pity that they chose this particular author to do it to. Perhaps they should... *gasp* write their own stuff and show us how really good they are! Better than that old Asimov, obviously.