I'm surprised WSTRN were chosen since they have a massive top 5 hit at the moment. Alessia Cara's Here is also massive in the US, I guess Radio 1 didn't put it on their main playlist so she could be part of the Sound of 2016.
Lots of interesting artists, NAO is definitely my favourite. I've seen Mabel a lot on Spotify, while Dua Lipa seems well promoted on Apple Music. Mura Masa has some good songs, while Section Boyz & Izzy Bizu seem interesting. Jack Garratt has some good songs, while I presumed J Hus was a novelty act (though I really like Lean & Bop).
I bet Halsey's UK label are panicking with her being left off this .