I'll say that I'm torn on this. I really liked the original, and there was definitely room for a sequel. But I have loved Disney's recent original projects- Tangled, Wreck-It Ralph, Frozen, Big Hero 6, Zootopia- and am heavily anticipating Moana, and I don't want Disney proper to end up like Pixar- stuck churning out sequels to their films because they're guaranteed sells. With this and Frozen 2 already confirmed, and chances of both a Big Hero 6 sequel and a Zootopia sequel pretty high, I just don't want to see Disney get caught up in the sequel rage.
I was also really looking forward to Gigantic, and am disappointed it's been pushed back to the end of 2018. I hope we get more news on it soon.
On a more positive note though, I'm glad it means we'll get two Disney Feature Animated films in the same year. I would look more kindly on Disney's sequel push if they were to balance it in a similar manner, with a sequel coming out the same year as an original project too.