Mechanics and lore, seeing what they did with the new FR books of removing anything from 4e because "most people got upset because of it" (this was the actual reason, as stated by the Tondro guy in Discord).
Gloomwrought is not a Shadovar city, tho. Some of them live there, but they didn't founded it. It's a city founded by people from other world of the multiverse.
And 5 Doritos later, they released Exandria, that made her the default goddess of death, with a lore more faithful to her original... So, like, I don't think making her a planar being was necessary at all. If that was even the reason for the change (that I really doubt)
My thing with humans is that I find playing them boring (as opposed to saying that they are boring). I'm already a human in my real life. Why would I want to play as one in my escapism? If I get to play a pointy eared human or a blue-skinned human over the just plain normal human, I will.
I think people has said this many times enough, but Session Zero is key. That and a mini document explaining the setting you want to play. It can be a single page document explaining the limitations and feeling of the setting.
In my experience, I know a lot of old guard GMs that complain about...
After this book destroyed my 14 year old campaign, I'm also looking for a new setting to play. Has Tales ever converted the dragonborn (dragonkin, I think they called them in Midgard) to their system? I think that if we are going to have a Dragon Sultana, I prefer the original over the cheap...
The price is indeed a bit high for me (taking into account that I have to convert my money into dollars first), but is definitely more accessible than the official books.