Important note. This information is not officially confirmed, and if it is correct, it is a large...huge spoiler.
Here are supposed to be official concept arts of new designes of G5 ponies.
The new generetion of My Little Pony will begin in 2020 with the new movie to present new art, new story and new ponies universe.
As you can see three ponies have changed their races. Fluttershy is no more pegasus but unicorn now, Pinki Pie on the other hand is new pegasus and Twilight is earth pony.
Opinions of the audience are already divided. Someone thinks that this is a complete nightmare, and someone see good in race changes to Twilight, Fluttershy and Pinkie Pie. Because now they define personality traits for each races:
Unicorn - Soft spoken and regal
Pegasus - Fun and full of energy
Earth ponies - Passionate in their areas of expertise.