Absolutely! I'm actually tempted to buy another copy of the set (without minifigs) so that I can have a couple of carriages on their way to Hogwarts. But for the casual, less obsessed fan, I can totally see why it's not a popular set. Even when the next FB film comes out (which presumably contains a scene with "Grindelwald's Escape") I suspect it will still not sell.
Yes, all of that is true. They can just put the Chamber set next to the Great Hall, and no-one will really have a problem with that. This is why I suspect the Chamber will be one of the Winter sets. My only real doubt is that the Basilisk was contained with the Great Hall set (which didn't really make any sense).
I think we're getting 5 sets. I guess 2 will be based on the new FB film, leaving 3 HP sets. However, the Diagon Alley mini-set that was spotted in Slovenia may not count towards that total - it's microscale and might be a freebie. So I'm hoping we get 3 other sets. If I had to put money on it, I'd guess Hagrid's Hut (mid-size), Chamber of Secrets (large) and Duelling Club (small). I'd love the first two, and my 5 year old son would love all of them, especially the Duelling Club, so Lego would be hitting on all demographics and releasing at a variety of price points. They can leave the Burrow to be released next year.
I'm sure they'll do another Knight Bus set. The Hogwarts Express set creeped into Book 3 with Lupin, Sirius Black poster and Dementors, so maybe the next wave will include sets from Book 3? If so, then the Knight Bus is very likely. Personally, I'd rather if Lego took it slow and kept the focus on Books 1-2 for the next wave, and then turned to Books 3-4 in the Summer. If they focus on 2 books a year, that will keep the line fresh for at least a few years.